I check in on
smart music periodically, which links to individual tracks available for free elsewhere on the internet. Normally it's from relatively established acts who are letting people download one or two songs. I'm very seldom thrilled by what I hear, but interested enough to keep downloading and every now and then there's some gem or some remix I don't have of a tune I do like.
I think I said somewhere else on here, but I went nuts and did a 20 gb trawl through net labels a while back and have found there's not huge amounts that I keep coming back to.
One thing I did really like is an EP by Blaktroniks called 'P2P Pressure'. It's minimal instrumental hip-hop bounce, sorta like Dabrye if anyone likes him, or maybe JayDee instrumentals. I can't link to it directly, cos the net label
http://www.tokyodawnrecords.com have done their site in Flash. The label generally covers similar territory to Sonarkollektiv or Kompost.
If anyone wants to read what I wrote about various net labels, the link is
here. It's for a web mag that deals in IDM type territory, and my tastes in that region are towards the soft and clicky end of things rather than your post-Autechre crunchy shit..