|OK, this is admittedly a bit nerdy, but I can't resist posting it. Above is a video from a Google TechTalk series with Luis von Ahn.
Here's what Luis talks about: some tasks are easy for you and I, but enormously difficult for computer programs. For example, looking at a photograph and identifying the objects. Sounds easy, but try to get a computer to do it accurately!
So how do you get humans to solve problems that computers cannot yet solve? The elegant answer: construct "games with a purpose." This makes me wish I was doing a CS degree.
[via Benj, thanks buddy!]