Remember those nature CDs that were all the rage a few years ago where you could buy Sounds of the Amazon or Babbling Brook? They were designed for relaxing purposes, but I'm pretty sure all they really accomplished was annoying the heck out of people. If you want to create a real peaceful atmosphere, however, you should check out the Sound Scape Stereo.
Conceived by Hyunsoo Choi, Hyori, Kim and Gisung Han, the Sound Scape Stereo projects calming images of natural world on to the surface in front of it via LED projector, creating a full-on musical experience. This may just be a stoner's greatest fantasy come true.