Almost forgot that tomorrow night into Saturday is the Notte Bianca. Basically, it will be an all night party/event happening almost all over Florence, with many things going on and several museums, etc. open very late or into the AM on Saturday. Wow. Should be crazy -
Some more info in English (the above is in Italian only):
http://www.turismo.intoscana.it/allthingstuscany/tuscanyarts/white-night-florence-2010/
http://www.discovertuscany.com/blog/events/a-sleepless-night-for-florence-1015/