Video Editing 2.0: 8 Ways to Remix Online Videos: "Jumpcut lets you upload video, photos, and audio, or import from Flickr or Facebook, and edit using a Flash interface. Add titles, effects, transitions, music, and split and crop video tracks. Then publish your video and let others remix it. Jumpcut also has some social networking features (like groups). Jumpcut is probably the best of the online video editors, though I really wish there was a way to export videos off the site.
Of the bunch, Jumpcut's editor most resembles the feel of offline editors, like iMovie."