I know, this may read crazy: I just came across this station on the web, who play nothing but the sounds and songs of different birds! It's winter here and I'm missing summer terribly, so this radio stream creates a summer atmosphere right in my living room - crazy, but nice (and nobody gets hurt, either ;-))

P.S.: The link may not work in your browser - the station is actually listed on iTunes under "radio" and "Ambient".