From the moment YouTube launched, viewers have developed ingenious ways to manipulate the unlimited store of videos contained on the site. See below for a few choice web-based tools-slash-art projects that allow you to do everything from crossfade to add a cascade of blood drops. Feel free to contribute additional links in the comments section.
2YTVMFCF dot com is made by JAKE ELLIOTT (dai5ychain.net)
big ups CHIwebz
You3b http://www.you3b.com/
Lol, its hard to remember the second domain.
from a while ago:
http://www.artisopensource.net/2008/09/18/mashinema/
Thanks for sharing these. I checked them all out. I like them.