Here's a few more:

MHIG = My Hand is Good

VPIP% = Voluntary Put in the Pot %

Dwarfie= A young, british poker player that makes liberal use of stacked phone books to reach the table.

x BB/100 = winrate expressed as Big Bets per 100 hands played

STFU = Shut The F*** Up = not an expression usually found in FTR posts (we're too nice to each other to use terms like this), but certainly one you might come across in the chat box of your favourite poker site