• Joy Wants Eternity - Music at Last.fm
  "From a basement in Seattle, Washington, 15 strangers met together in response to an ad welcoming all instruments for experimenting with walls of noise."
• Grace Cathedral Park - Music at Last.fm
  "Grace Cathedral Park keeps you floating in dreamland on a Sunday morning. Their songs are epic no matter what the length is, and in some cases the song can actually last for 20 minutes."

There's more where this came from at del.icio.us/ambientmusicblog.