ofxSlitScan is an addon for openFrameworks that lets you do time warp distortion and video delays in real time.
It works by keeping a lot of video frames in a big buffer and resampling them based on a delay map that you provide.
You can use it as an addon in your own projects or run the binary. The binary lets you load your own delay maps and videos to play around.
Currently the binary is OS X only. Want to help me make a Linux and Windows version? Go for it! I'll post it here.
A classic example of a film that features slit scan is The Fourth Dimension by Zbig Rybczynski. A few music videos too, like this really pretty one for Muse.
For more inspiration and examples Golan Levin has put together a big list of slit scan appearances in in new media and video art.
I used this to create some of my videos. My friend Tivon Rice used it in his installation "A Macrocosmic Zero" to create video delays.