The skill Spot has epic uses and is useful to all but blind adventurers. It's one of those skills that if a character can he should put maximum ranks in it. But, even if he does, it's a good idea to have the skill even higher. I've drawn from a variety of sources in this list; abbreviations are available here.

Improving Spot Skill Checks with Spells

The best items for improving Spot skill checks are wands. A creature with a non-negative Charisma modifier and but 1 rank in the skill Use Magic Device (PH 85-6) can make Use Magic Device skill checks to use a wand (DC 20) until he succeeds by rolling a 19 or 20 (or until he can't use the wand that day by rolling a 1) and improves markedly his chances of (eventual) success with minimal investment. The real key is finding the different kinds of bonuses to one's Spot check so all of those bonuses stack. Conveniently,¹ I've done that below.

• The 1st-level Drd spell raptor's sight [trans] (RW 175) for 1 hour/level grants the caster, among other benefits, a +5 competence bonus to Spot skill checks.
• The 1st-level Sor/Wiz spell eyes of the avoral [trans] (BE 99) for 10 min./level grants a touched creature a +8 racial bonus to Spot skill checks.
• The 1st-level Rgr spell embrace the wild [trans] (SpC 79) for 10 min./level grants the caster, among other benefits, a +2 bonus to Spot skill checks.
• The 3rd-level Sor/Wiz spell vision of the omniscient eye² [div] (DM 74) for 1 min./level grants the caster, among other benefits, a +10 insight bonus to Spot skill checks.
• The 3rd-level herald spell eagle eyes [trans] (Dragon Annual #5 87), for 10 min./level, grants a touched creature, among other benefits, a +20 bonus to Spot skill checks.
• The 3rd-level meditation Domain spell that art thou [div] (OA Web enhancement "The Mahasarpa Campaign Setting: A Campaign Option Web Enhancement for Oriental Adventures" 8) for 1 round/level grants the caster, among other benefits, a +20 bonus to Spot skill checks.
• The 4th-level Drd spell essence of the raptor [trans] (SpC 84) for 10 min./level grants the caster, among other benefits, a +8 bonus to Spot skill checks.

This list, of course, ignores the myriad of ways spells can improve skills in general (e.g. the 1st-level Brd spell improvisation [trans] (SpC 121), the 2nd-level Clr spell divine insight [div] (SpC 70), the 2nd-level Clr spell guidance of the avatar [div] (Spellbook column "Guidance of the Avatar")).

This list also ignores the far rarer handful of ways to improve all of one's Wisdom-based skills--including the Spot skill--by toying with one's Wisdom (e.g. the 2nd-level Sor/Wiz spell owl's wisdom [trans] (PH 259), the 2nd-level Drd spell animal spririt [div] (MoI 98-99), the 5th-level Drd spell owl's insight [trans] (SpC 152), the 8th-level Sor/Wiz spell necrotic empowerment [necro] (LM 68)). Many are higher level effects, restricted not to wands but to scepters (LE 8) and even staffs (PH 92).

One of the biggest problems with making Spot skill checks is the massive and unreasonable -1 penalty per 10 ft. of distance (PH 83). It's likely the DM will waive this in many cases lest absurdity ensue, but if he doesn't...

• The 5th-level Sor/Wiz spell dragonsight [trans] (SpC 73) for 1 hour/level grants the caster, among other benefits, the ability to suffer only half the normal penalties for distance when making Spot skill checks. Note: Other spells reduce penalties to attack rolls for distance, which, while useful, doesn't actually help see stuff farther away. This spell does. Also see Custom Magic Items, below. Finally, this spell must be placed in a scepter or staff; its spell level precludes wanding.

Improving Spot Skill Checks with Items

Most magic items granting bonuses to Spot skill checks grant competence bonuses. Nonetheless, some don't, so below I grouped items by bonus type then arranged items by price. Included are more interesting, obscure, and higher-bonus-providing items; omitted are many redundant or uninteresting items.

Alchemical Bonuses

• The alchemical item prickly tea (Dragon #301 54) (50 gp; 0 lbs.) for 1 hour grants the drinker, among other benefits, a +1 alchemical bonus to Spot skill checks.
• The religious equipment mordrei'in (FE 153) (25 gp; 0 lbs.) for 10 minutes grants the user, among other benefits, a +2 alchemical bonus to Spot skill checks. Note: Unique to the Eberron campaign setting. Also, it's a mild poison, so the user risks Constitution damage.

Circumstance Bonus

• The tool and skill kit item masterwork tool (PH 129, 130-1) (50 gp; 1 lb.) for the skill Spot grants the user a +2 circumstance bonus to Spot skill checks.

Competence Bonuses

• The face slot item eyes of the eagle³ (DMG 256) (2,500 gp; 0 lbs.) grant the wearer a +5 competence bonus to Spot skill checks. Note: Useful if restricted to core rules.
• The head slot item skullcap of eyes (DrU 101) (5,500 gp; 0 lbs.) grants the wearer, among other benefits, a +5 competence bonus to Spot skill checks.
• The face slot item third eye aware (MIC 140) (10,000 gp; 0 lbs.) grants the wearer a +10 competence bonus to Spot skill checks.
• The throat slot item dragon's eye amulet (MIC 95) (55,000 gp; 0 lbs.) grants the wearer, among other benefits, a +10 competence bonus to Spot skill checks.
• The armor/robe slot item robe of eyes (DMG 265) (120,000 gp; 1 lb.) grants the wearer a +10 competence bonus to Spot skill checks. Note: Given the price, probably not useful if restricted to core.

Insight Bonus

• The face slot item crystal mask of insight (MIC 91) (20,000 gp; 0.5 lbs.) grants the wearer, among other benefits, a +9 insight bonus to Spot skill checks.

Profane Bonus

• The face slot items spider mask (black widow) and spider mask (brown recluse) (Dragon #298 47) (56,150 gp and 37,840 gp, respectively; 0 lbs.) grant the wearer, among other benefits, a +4 profane bonus to Spot skill checks. Note: Once donned, a mask is pretty much worn permanently. As a bonus, the masks look horrifying.

Unnamed Bonuses

• The alchemical item hawk's ointment (CAd 118, 119) (50 gp; 0 lbs.) for 2 minutes grants the user, among other benefits, a +1 bonus bonus to Spot skill checks. Note: Penalties apply after duration expires.

• The held item crystal anchor of alertness (MIC 155) (2,500 gp; 0.5 lbs.) grants the bearer the ability to take a standard action that leaves the item "planted in the ground" to grant for 1 hour 3/day allies within 30 ft., among other benefits, a +5 bonus to Spot skill checks. Note: Obviously for keeping watch, it'd be a useful item for setting ambushes were it not shedding light like a lantern.

• The face slot item raptor's mask (MIC 210) (3,500 gp; 0 lbs.) grants the wearer, among other benefits, a +5 bonus to Spot skill checks. Note: If getting insight and competence bonuses to Spot skill checks from spells, this is what a creature wears.

• The face slot item goggles of draconic vision (MIC 107) (16,000 gp; 1 lbs.) grant the wearer, among other benefits, a +5 bonus to Spot skill checks.

• The head and half-face (i.e. the creature can wear, for example, a single lens) item eyes of the spider (CSQ 129) (212,000 gp; 0 lbs.) grants the wearer, among significant other benefits, a +4 bonus to Spot skill checks. Note: The wearer also probably looks like Locutus of Borg.

  

Custom Magic Items

A creature may be able to create--using Table 7-33: Estimating Magic Item Gold Piece Values (DMG 285)-- a custom item that grants a competence bonus to Spot skill checks of whatever bonus the creator wants. Such an item's cost to create, market price and prerequisites, however, are exclusively the DM's call, and the first thing the DM is supposed to consult when a creature crafts a custom item is a list of similar items. The list above is that list of similar items. That means while Table 7-33 says that the goggles of spotting (250,000 gp; 0.25 lbs.) that grant the wearer a +50 competence bonus to Spot checks is totally legit in a vaccuum or if the DM's a goldfish, such goggles of spotting are unlikely to keep those statistics--or even exist--in normal play with a normal DM despite Table 7-33. That's because Table 7-33 is the last place one goes for finding a magic item's special abilities, cost to create, market price, and prerequisites--not the first--, and most published non-epic magic items that grant skill bonuses top out at a +10 (usually named) bonus.

I believe enough items grant raw bonuses to Spot skill checks to render creating new ones unnecessary, but a custom magic item granting the wearer the feat Hawk's Vision (CAd 114)--probably a pair of goggles weighing 0 lbs. and probably costing 25,000 gp based on the Arms and Equipment Guide's sidebar Magic Items that Grant Feats on page 128--is a good investment for the dedicated spotter. One of the feat's effects is to reduce the Spot check penalty for distance to -1 per 20 ft. instead -1 per of 10 ft., effectively doubling the user's spotting range. However, unless the wearer possesses the supernatural ability wild shape (e.g. like a druid), the wearer must employ the skill Use Magic Device to emulate the class feature wild shape (probably of a druid unless the DM allows otherwise, therefore DC 25) then use the virtual class feature to activate the custom magic item like Lidda uses the class feature turn undead that she doesn't possess to activate nonetheless the magic chalice (PH 86). The DM, of course, has the final say how this process works; the skill Use Magic Device is a mine field.

Combining Spells and Items

A creature can combine the different named and unnamed bonuses spells grant with the even more different named and unnamed bonuses items grant for a potentially enormous bonus to Spot skill checks, but bear in mind this will likely greatly annoy DMs who enjoy monsters surprising PCs.

1. I'm really not that crazy. A PC in one of my campaigns is using a homebrewed archer class with access to these spells, so I'd already done the research. That PC's bonus to Spot skill checks is outrageous.
2. The spell vision of the omniscient eye is amazing, and I urge creatures who can to add it to their spell books or spells known and those who can't to buy a wand of it and, if they've no wand in it already, put that wand in their primary weapon's wand chamber (Du 34) (100 gp; 0 lbs.).
3. In the Dungeon Master's Guide (2000) for Dungeons and Dragons, 3rd Edition the eyes of the eagle (DMG 216) (1,000 gp; 0 lbs.) and the robe of eyes (DMG 225) (90,000 gp; 1 lb.) granted much more interesting circumstance bonuses to Spot skill checks (and the robe granted +15). These became competence bonuses in Dungeons and Dragons 3.5 (and the robe dropped to +10).

Dragonborn and raptorans (Races of the Dragon and of the Wild, respectively) gain flight as racial features. They do not gain it until 5th-6th level, but it costs nothing more than your choice of race.

Dragon and dragonblood characters can take Draconic Wings at first and Improved Draconic Wings at sixth for flight; you are limited in how long you can fly at a time, but with brief landings you can fly all day. Both feats are from Races of the Dragon.

For other races, the most cost-effective answer is the feathered wings graft from Fiend Folio. They cost 10,000 gp for permanent, nonmagical flight. They also will drive you mad if you are not Evil.

For more options, see Ernir's Lists of Necessary Magical Items.