Wow... this is fairly interesting. I tried something I thought would be moderately obscure, "The Book I Read" by Talking Heads. It countered with a thoroughly accurate description of the song and countered with ZZ Top "Cheap Sunglasses" and Bob Dylan "Neighborhood Bully". Very interesting choices...

I don't know if this has been mentioned here, but I noticed the 5.1 version of Winamp has something called "MusicMagic Mix" in the media library. It seems to work like Moodlogic did, but appears to be free. It only works on your personal collection and can make purchase suggestions. One thing I found very interesting is if you run it on it's "low variation" setting you get a very accurate playlist that gets very boring after a few songs...