http://www.nytimes.com/2009/07/25/nyregion/25bear.html?pagewanted=1&_r=1 (NYT -- registration may be required)
Basically, they have these food containers that require you to press a button, turn it half way, press another button, and turn it the rest of the way. At least one bear (named 'yellow-yellow') figured out how to open it.
For what it's worth, some humans can't figure it out. I especially liked this comment somebody made, "Turns out there is considerable overlap between the stupidest human and the smartest bear."
Are you the new RSS feed? Have you taken over my old position? haha