Yep, mosh pit's still in use in the UK, and though I've never been to one, I know quite a few who have - it's a place at the front of a relly loud rock concert where everybody pushes and shoves to get as far forwards as possible, in time to the music(well, sort of...)
Other 'in' words include: (As far as my experiences go, this is UK only)
boom! - cool/brilliant/amazing
heavy! - see above.
random - strange behaviour, changing the conversation to an irrelevant topic, anything unusual.
dodgy - applied to anything suspicious relating to people trying to cheat you or (usually) people/objects with apparently perverted intentions. (Euthemising furiously - e)
manky - horrble/disgusting/old/ugly (applied to inanimate objects.
crusty - see above.
boffin/boff - anyone who works hard at school/gets good grades/teacher's pet etc.
(you) div - stupid/idiot (usually a jokey, affectionate term)
bad/rude girls/boys - people who regulary get in trouble, say stuff like boom and heavy, are rude and spiteful to everyone. (group term, and they're proud of it!)
wicked - cool (less common)
cool - cool (still cool to say cool!)
well good/bad/ugly/nice - alternative to very or really.
shame! - hard to explain, it kinda means ha ha! Like, when someone does something wrong or are told off, spoken forcefully.
sad - often used to describe boffins
yeah man - agreement
like - this is, like, used all the time, like, but don't like, overdo it!
I hope you found this helpful, but beware: it's not cool for an adult to try to be cool... I wouldn't advise most, especially teachers, to use these words (with the exception of the more widely known ones) unless you are fully familliar with them and uset he rest of the lingo - or you may end up being labeled 'sad' or even, 'dodgy'!
EDIT: Oh yeah, and way is way out in the UK! (maybe except for surfers)
EDIT(2): Wayer was never in.
If the world doesn't suck, we'd all fall off.
