I've been wanting to try this one ever since I read about it in one of my favorite blogs, Mighty Optical Illusions. Technically, this is called cylindrical mirror anamorphosis, done here with a television so that I can animate the material that is displayed. As you can see, I have placed a reflective cylinder on the screen. The image is warped so that when it is reflected by the cylinder, the curvature unwarps it, resulting in an undistorted image appearing on the cylinder's surface. You can read more here, for example.
Cylindrical Mirror Anamorphosis from dep on Vimeo.
The cylinder I used could be smoother - I found this one in the trash.
Update 24.7.2010: Shortly after publishing this video, I came across Ross Ching's Distortions. His execution is far better than mine, check it out:
As a bonus, here's a video of a recent experimental piece that I did. It participated in the Nokia Ubimedia 2010 competition as an interactive ambient media installation. It's also made with vvvv, and inspired by a video I once saw of a certain kind of feedback effect. Sadly, I can't find said video any more (I have since started using Tumblr to store cool links).
Video Installation from dep on Vimeo.