Thanks to Sha Hwang, you can now siltscan videos on YouTube and Vimeo with an easy-to-use bookmarklet. Just go to the video and click. In case you're unfamiliar with the technique, here's a description from Golan Levin:
Slitscan imaging techniques are used to create static images of time-based phenomena. In traditional film photography, slit scan images are created by exposing film as it slides past a slit-shaped aperture. In the digital realm, thin slices are extracted from a sequence of video frames, and concatenated into a new image.
Be sure to switch over to HTML5 on YouTube or Vimeo first. The bookmarklet won't work with Flash.