PBS aired a fascinating documentary earlier this year about an orangutan that was taught sign language in the 70s by being raised on a college campus as a "human child", explores both the personal side and ethical issues. I was surprised I had never heard of him, and even more surprised to find that he now lives at the zoo a few miles from my house. I had no idea.

Video here, I'm not sure if this plays outside the US: http://video.pbs.org/video/2365286726/