Check out Nickel Creek or Mutual Admiration Society. Excellent accoustic music. Their first CD was bluegrassy their second, "This Side", was totally different. Here's a link to some of their videos.
http://launch.yahoo.com/artist/video...tistID=1049618
Smoothy Song is an instrumental that in my opinion just kicks ass. These guys are in their early to mid 20's and have been playing together since they were around 6-8 years old. Each one of their CD's has been a total departure from the previous.
MAS is basically Nickel Creek and Toad the Wet Sprocket. Good stuff.