As part of a review of electronic submission in the College, I’ve stumbled across a couple of links which are useful if you are worried about signing away the rights to your work when you upload it to a site. In his blog post, Give Away Your Videos, Not Your Rights, Chris Potter summarises the terms of service for YouTube and Vimeo amongst others.
The website, Terms of Service; Didn’t Read (http://tos-dr.info/) summarises rights issues for a number of websites through a traffic light system.
This is a minefield and you might find it helpful to have an IP lawyer at hand before you press the Upload button!