What is your source for discovering new music?

I second 90.7 WFUV in new york it's member supported and streaming on the web. disclaimer: I'm also a member. It's not an exageration to say They're probably the first station to play Adell, Amos Lee, Norah jones and John Mayer. They even have their own recording studio where all sorts of artists come in and record songs which become available on cd during their member drives. They're called City Folk live. All excellent and from what I hear fetch a pretty penny on ebay

I go to a few review blogs:
Blastitude
Brainwashed
Still Single
Tiny Mix Tapes
sometimes pitchfork.

Some bulletin board chatter:
Board.crewcial
Termbo

Yes on FMU.

I talk to people at record stores and ask them, what are you listening to. I buy about 10 LP's a week, some 7"'s, tapes.

I run a record label so new music is always welcome to my ears.

I go to thrift stores, used shops and dig as well.

A nice stereo is great, but its to play the music for me.

I am a VMPS speaker owner/agent since buying the speakers and have many listeners over to hear them. They bring their music, much of which is both excellent sounding and good music. I then go on Amazon.com and order them up on cd. Also, I ask the guys and gals who buy and sell equipment from me what some of their favorites are and I often buy what they recommend and sometimes their picks are awesome in every way.

Have a party and let everyone take turns playing their iPOD

Last fm, googling for internet radios, and recommendations from guys on forums.