I was thinking about making a list of useful project management/collaboration tools, but I stumbled upon this blog post while eating my morning cereal. About 2 years ago I was searching desperately for tools like these and came up pretty disappointed. The only good that came from that search was Basecamp, which I've used pretty extensively. Google docs is also a must have...if you trust Google with your privates ;)
Based on his recomendation, I'm off to play with Klock. I need a new Air app to toy around with.