Well, I've just gotten into experimentalism and minimalism as of recently. I've bought an album by the Kronos Quartet, but that's as far as I've gotte. Does anyone have any reccomendations for all of the post-modern genres? It would be even cooler if you guys could send me files on the computer, but if not it's all gravy.

well.. the big four in minimalism are La Monte Young, Terry Riley, Steve Reich, and Philip Glass. Terry Riley is probably my least favorite of the group though. ill send some files over aim if you want

Sure, if you want. my nAIM is: no pants yufice.

Do you like John Cage Yufice?

the Kronos Quartet do all covers, adaptations,etc so saying your into Kronos means you are possiblly into a lot of stuff . . .
grabbed from allmusic.com

Kronos Quartet
Performed Works By
Terry Riley
Philip Glass
Osvaldo Golijov
Kevin Volans
Steve Reich
Arvo Pärt
Alfred Schnittke
Astor Piazzolla
John Adams
Henryk Górecki
Sofiya Gubaydulina
George Crumb
Alban Berg
Traditional
Peter Sculthorpe
Thomas Oboe Lee
John Cage
Ken Benshoof
Franguiz Ali-Zade

also jazz covers like Ornette Coleman, T. Monk, etc

Great sites to check out for adventurous modern music:

http://www.innovarecordings.com/
http://www.newworldrecords.org/
http://www.emf.org/
http://www.rermegacorp.com/
http://www.electroshock.ru/
http://www.mode.com/
http://www.centaurrecords.com/ (specifically their electroacoustic section)
http://www.lovely.com/

Those ought to give you a good start!