1) www.delicious.com -  Delicious is a tool to save,organize
and discover interesting links on the web. I think its social bookmarking.

2) www.animoto.com - Animoto is used to make short animation videos for free and you could use it for educational, business and own use purposes! I think its a web authoring software

3) www.blogger.com - Blogger is used to make or give people their own domain and allows them to share their interests with the world. You can't upload powerpoint or large documents like that, but you can upload photos and videos.