My favorite sites are Discovery Education and YouTube. DE is great especially for science and helps build background knowledge to enhance curriculum. YouTube now has videos in so many areas - lots of how tos, instructional supports, and interesting ideas.
As to the copyright and fair use laws, I LOVE the disney video explaining what's right and why - very child friendly and easy to understand. I didn't know that small parts could be copied if used in the correct context and in the correct nature. This would be a great video to show kids prior to research assignments.
Dropbox is really cool. I can create a file at home, with documents, pictures, and videos, and save them all to one folder in my Dropbox. Once I'm back at school, those files can be linked into my IPADS and laptops for my kids to use in stations and small group lessons.