(Mods, I looked around and wasn't sure where to put this... please move if there's a better spot)
In the course of my random web searching, I stumbled across this really awesome website. It's really good for relaxing to, and for helping you sleep (as I've found).
It's helped me lessen my anxiety and whatnot, so it's really cool (and it totally sounds like nature is inside your room).
Check it out at
http://soundsleeping.com