Can anyone shed some light on the origin of the use of the word "Bang" to imply a positive adjective?
For example, here are three colloquial phrases which use the word bang to lend strength to the meaning:
That's a bang-up job you've done!
That's bang out of order!
It's bang up to date.
Meaning, respectively:
That's a really great / the best job you've done!
That's really out of order!
It's the most up to date.
UPDATE
I've just thought of another one:
They had him bang to rights. (i.e. He was most definitely guilty)
I'm still confused as to where this usage originated. Brian Hooper suggests they could all be a variant of bang-up, which sounds plausible.
It would also appear from the comments that a few of these uses (which I can attest are real and recognisable phrases. Well, in England, at any rate) are unfamiliar to our American friends. So perhaps these are colloquialisms that haven't migrated for some reason, or perhaps they are more modern constructions. I will continue to search.
UPDATE 2
I've come across some interesting information regarding the origin of the phrase – it appears in one of Dickens' works, Sketches by Boz, where the term Slap-bang is used to refer to a cheap restaurant.
The deal was that both money and food were slapped down on the table because it was a cheap establishment. From this we get the terms slap down and bang down, which seem to have evolved into bang-up and slap-up respectively as their positive opposites. Slap-up seems to be heard only with regard to food (a slap up meal), whereas bang-up seems to have become a more general expression of positivity.
This still doesn't quite satisfy me with regard to the other uses (bang out of order and bang up to date), but it's a decent start.
Best Answer
It's slang. A bang up job is an expression in itself even if it might come from some other use of bang. However, bang used that way is usually a positive adjective, not a superlative.
On the other hand, something that is banged up is usually broken. You should be careful when to use the expression, as a bang up job could easily be mistaken by someone not familiar with both expressions for a job causing something to be banged up, i.e. a lousy job.
It's used both in UK and in the states. Perhaps symptomatically, in the states it seems to be more used for sex, crime and drugs. ;)