If you're interested in supporting Mozilla or OSS projects in general, Mozilla is actively soliciting people to participate in testing their new calendar systems. Sunbird and Lightning, as they are called, will soon go into public testing, and Mozilla wants people to understand and embrace the ability to submit information regarding flaws/bugs in the software. As such, until tomorrow, Test Case Writing Day is a go. It's actually pretty neat, if you are into this sort of stuff. Take a look.