If you're not already exhausted on September 7 after trying to check out M.I.A., Stars, The Hidden Cameras, k-os, and You Say Party! We Say Die! playing for free for U of T and Ryerson's frosh, why not throw in a little free Yeah Yeah Yeahs for good measure?
That night––if you're still looking for time to kill and bands to see––Vice, Rimmel London, and CKIN2U are hosting the Yeah Yeah Yeahs at the Berkeley Church (315 Queen Street East) for the Festival Ball. Starting at 8 p.m. (with Karen O., Brian Chase, and Nick Zinner on at 11), it's 19+ and includes free drinks.
To get in (it's guest list only), you have to RSVP at festivalball@viceland.com, and even then there's no guarantee: according to Chromewaves, it'll be first-come, first-served. Good luck.
Photo from the Yeah Yeah Yeahs Project. Thanks to Daniel N. and Laura R. for the tips.

Newsstand: November 23, 2009
I think the guest list may be closed now - some people who rsvp-ed haven't got a confirmation autoreply back.
It is (at least according to a rep from Vice) for sure still first-come first-serve for the evening...
First come, first served...if your name is on the guestlist.