As a full-time student who juggles studying, class, homework, a part-time job, some semblance of a social life, and a girlfriend (this is where it gets tough!
), I have to constantly find ways to relieve stress. It depends on the day, my mood, and what I'm studying... but two things that always work are laughing with friends/the girlfriend OR listening to music. And like others have said, Jazz is something I listen to pretty regularly (somebody mentioned Medeski Martin and Wood... great stuff. Also Coltrane, Herbie Hancock, Chick Corea...).
I take it one step further and I play in a Jazz Quartet (I play drums, there is a pianist, guitarist, and vocallist) as often as I can - big time stress reliever! We do alot of improv instrumental stuff that is alot of fun, and play some classic standards. It doesn't hurt that I get paid to do it, too
.
Stress is a constant battle in my life, but I've found that simplifying things, taking it in "chunks", and doing things like I mentioned above when I can tends to really help keep me sane.