Small business software firm 37Signals has created a proof-of-concept whiteboard as an iPad web app and made it available for free to anyone. It's called Chalk and is available at chalk.37signals.com. It's really simple but quite handy. I just added it to my iPad's home screen and I look forward to using it.

There's some HTML5 and some advanced CSS in the app. There are more powerful alternatives available online, but if you don't already use one of them - why not give this one a try? Check out the screencast demo below.