Wow... just heard about this wonderful new site for finding and uploading music. Jamendo is open source. Their tagline says: "On Jamendo artists allow anyone to download and share their music. It's free, legal and unlimited." It's nice to have a leagal source for music when creating videos with children. Some of the pictures from the album art on the site are not for elementary school students, so make sure if you are having them use these materials that you download the music for them to use.
Another site that touches a librarian's heart is webcitation. Have you ever had a student cite a website only to have that website not come up or give you an error message when you tried to check the source? Well, webcitation can solve all that. I have just signed up but have not used the site yet. Bacically it works by adding a bookmarklet to your citation page instead of just a URL. The bookmarklet will lead you back to the actual page, as it looked, on the date the student accessed the page. Now there will be no more padding of citations, students will actually have had to use the site... or will at least have to visit the site to have the proper bookmarklet.