I just finished a search for a TV mount for inside my rig. (I'm getting one from Sanus)
Along the way I did see some that fold down, like for an under the counter application. Also some ceiling & specialty mounts. Check these sites:
http://www.monoprice.com
http://www.sanus.com
http://www.premiermountscentral.com
http://www.cheetahmounts.com
http://www.omnimount.com