music recommendation systems

Hello and greetings,

Some time ago I heard of many on-line music recommendation systems (you
tell them what music you own and they use correlation to recommend music
for you).  I've been playing with Amazon's system, but it seems too biased
by most recent entries instead of taking into account all ownings. Has
anyone played with a system that they enjoy?  Suggestions will be greatly
appreciated.

I wish all well.

						Jeff Johannes