there was an interesting site I found a long time ago, you typed in a band's name and it brought up a chart, kind of a 3-dimensional network of spheres with band's related or similar to the one you started with, then you could surf through, starting from that one common factor. I wish I could find it again, it's pretty cool. I thought it was related to the Pandora site, but I guess not...
Under the Radar Magazine:
http://www.undertheradarmag.com/
UtR magazine is really cool, I just got a stack of them from one of their editors. It's a good way to scope out up-and-coming bands. I think it's printed quarterly though, so there aren't many of them.
I used to get CMJ New Music Monthly
http://www.cmj.com/
discovered a ton of bands from that mag, and the CD comp they enclosed. I liked that a lot, but the last couple years got pretty hit and miss and I let my subscription lapse. I don't know how it is these days.
oh yeah, I like lastFM a lot, it's been good for our band, but I haven't really found too many other bands there. It's a cool setup though
I'll also surf the music section of Myspace, entering bands I like as a search parameter to find bands that claim to be influenced by or sound like them.
