Here's what seems like a cool site I just came across if you want to refresh material, learn new stuff, or maybe as a resource for current classes. Free courses on wide variety of subjects. Not for credit mind you...purely for knowledge and application values. I've forgotten most of my college algebra...prolly gonna check that out myself.

http://www.free-ed.net/free-ed/FreeEdIDX.asp

Note that there's a course on music theory as well.