Minecraft – With Minecraft Xbox 360 version, am I able to voice chat with the friend without using the phone

According to the Minecraft Wiki, the Xbox version is closest to Beta 1.8.2. It is expected to be updated again.

Here are a few key differences between the versions. The full current list can be found here.

• Local 4 player split-screen multiplayer (requires HDTV, won't work on SD)
• Limited to 8 player online play (apparently cross platform multi, but not too sure about that)
• Newly designed crafting system
  • Seems to use a list for crafting, so you don't need to remember recipes
• World's limited to 862x862x128 blocks (PC is ∞X∞X256, expected to be increased in later versions)
• Cannot change difficulty mid-game
• Can't use mods, texture packs, or add player skins (8 skins included in game)
  • Texture packs and mods support is expected much later
• Includes tutorial mode
• Kinect support is expected to be added later

EDIT:

As of October 12th, 2012, the Xbox version was updated to include all features listed (here)

The map item on the XBox 360 version of Minecraft works similar to the PC version, with three main differences:

1. XBox version gives you a free map at the beginning of the game. In the PC version, you must gather the necessary resources to craft a map item.

2. The PC version world size is (essentially) unlimited. The entire world in the XBox version is less than 1024 x 1024 only 864 x 864. The PC version of the map extends to the edges of the paper, the XBox version has wider "margins":

3. Every map crafted on the PC version is different; it covers a 1024x1024 area centered where the map was originally crafted. All crafted maps in the XBox cover the entire 864 x 864 world, centered at (x=0, z=0). In fact, each crafted map in the XBox version is an exact copy of your original map, including all mapped areas. Even if you throw your map in lava or lose it after respawning, any new map you craft will be populated with all areas you'd previously mapped.

Regarding the other questions:

• How many game blocks make up a map pixel?
  8 game blocks per map pixel.

• How big is the map/world?
  Now that the update has been released, we can confirm that the world is 864 x 864 (although you cannot mine or place anything in the outermost block, making it effectively 862 x 862). That makes the map 108 x 108 pixels.

• What does each color represent?
  Each pixel has a primary color based on what material is most represented in the 8x8 blocks (as visible from above). Most should be obvious (snow, ice, water, sand, grass, trees), but see the chart on this page for the materials that correspond to each base color. This base color is then shaded based on terrain elevation.

• How is it oriented?
  There are two conflicting evidences for orientation: if we assume that the top of the map is North, then the Sun on the XBox version actually rises in the North and sets in the South (in the PC version this was fixed in beta 1.9.4). Alternately, you could say that the Sun behaves properly (rises in the East and sets in the West), and that you are holding the map so that North is on the left (but this would be an unusual way to hold a map). As such, any discussions that use cardinal directions (N, S, E, W) should clarify which they mean.

• Is there any way to determine an approximate map location from (X, Z) coordinates?
  Since the game update was release on June 15, 2012, the map shows the coordinates of your current location. Here's a brief explanation:

  • The center of map is (x=0, z=0) (the crosshairs are slightly below that point, don't use the crosshairs to determine the center point).
  • Unlike normal integers, there is both a +0 and a -0.
  • X coordinate is left-right on the map: right is positive, left is negative.
  • Y coordinate is depth/height: 0 is the bottom-most bedrock layer.
  • Z coordinate is up-down on the map: down is positive, up is negative
  • Since the xbox map/world is only 864 x 864, that means that the max reachable coordinates are only +/- 432. In addition, the edge of the XBox world nearly always ends in the ocean (see map image above), so I suspect that some of these furthest outside blocks may not match those same locations in the PC map.

Here is how maps work in multiplayer:

• Each player has their own, independently drawn map.
• If a player crafts a map, it becomes a copy of their own original map.
• You can "share" map contents with another player by giving them your map and having them view it. Both player's maps will update with all visited areas.