Forbes says that Jumpcut is the most promising service among web based video editors. They compared JumpCut with MotionBox and PhotoBucket from MySpace but surprisingly missed Adobe Video Remixer available on YouTube.
"Jumpcut makes it easy to duplicate a video, so you could add multiple effects by cutting a video into two pieces, doing the editing separately, and stringing the two together. Jumpcut lets you upload any song. Jumpcut is ad-free.
It has a clean, simple interface with horizontal bars detailing elements of the video, which include sound and special effects. Yet despite Jumpcut’s approachable look, it doesn’t let you control the timing of anything. A song plays for the entire video, or it doesn’t play at all. It is similarly not possible to control when a special effect, like a "Ken Burns" zoom, happens." Link.