Discovered this new tool on Twitter today: Creaza --video editor which works with any camera device
No need to worry about codecs and extensions....
From the website:
Shoot and capture media with your mobile phone or any camera device, and sync it to your private media library in the cloud.
Shape and edit your media clips with professional-looking titles, transitions, effects, animation, music and narration.
Share and collaborate in an online workspace and publish your movies to social networks and video scrapbooks.
This one looks like a winner for classroom projects. A sharing/collaboration features allows you to invite others in to edit the film. It's all stored in the cloud and even allows for HD - movies can be exported with a resolution up to 1080 pixels. No installation or software is required and all files are safely stored.
I signed up for the waiting list; it's in Beta right now and will hopefully be getting an invitation to try it soon.