I recently had the opportunity (need) to mount a new AirPort Extreme Base Station and a couple Apple TV's. The best products on the planet for this come from H-Squared. I'm a long time fan ever since the new AirPort Extreme (the square one) came out. After visiting their booth at Macworld, I saw that they also had mounts for Apple TV 2 (the tvTray). I ordered a couple and have been just as happy with these as I have been with my AirPort and Mac mini mounts. If you've got the need to mount your Apple gear on the wall/ceiling chances are H-Squared has a solution.
As a side note I'm a believer that the higher you can mount your AirPort Base Station, the better the range will be. I proved it by mounting a NEW AirPort Extreme on the 2nd floor (phone closet) of my 4,800 sq ft. studio and it covers the entire space from end to end! I'm blown away by the range I get.
Check out their website here.