WeVideo is an easy to use, yet slick and effective browser-based video editing platform that lets you share and collaborate with others, it is available as  a YouTube plugin at  http://youtube.com/create  -  choose the WeVideo  editor


See also http://www.wevideo.com/ where it is available in 'free' and 'paid-for' versions.

Via theo kuechel, João Greno Brogueira