Robin Good: Loopster is a web-based free video editor which allows you to easily upload, edit, share and download your favorite video clips.
The service utilizes a traditional timeline and offers the option to edit individual clips by trimming their start and ending point, to add text captions and overlay titles, transitions, and audio effects and a soundtrack.
The final edited clip can be downloaded in .MPG format or shared directly on anyone of the major social networks.
The service is free to use.
More info: http://www.loopster.com/
(A big thank you to Giuseppe Mauriello who kindly discovered it and suggested it)
Via Robin Good, Jim Lerman, tom jackson