Skrbl: Online Interactive Whiteboard

Here's a great Web 2.0 tool:

http://www.skrbl.com/
Simple and easy online multi user whiteboard, start skrbl, give out your URL & start working together. Sketch, text, share files, upload pictures all in one common shared space. There are no new tools to learn, nothing to download, nothing to install. Brainstorm on our simple whiteboard to start thinking together, everyone sees the same screen, everybody gets on the same page.