Pokerstars is offering a 20% bonus for up to $120 ($600 deposit). It runs until Thursday (7/28) at midnight. You have to earn 5X as many FPP's as the bonus, so for a $100 bonus you need 500 FPP's to unlock. I don't see anything about a time limit to unlock it.

Information here:

http://www.pokerstars.com/depositbonus20.html

Whoops, didn't see that this one had already been posted, my bad.