Programmers' resources

I've recently been doing some Ruby coding and thinking about having a go at Python (VPython looks like fun!). I mentioned PLEAC in passing in my previous post, but another interesting site is Stack Overflow, which cropped up in response to a Ruby question I was googling. The odd thing is that I've never really used Stack Overflow before, despite the fact that it's been created by two guys, both of whose blogs I subscribe to. It has obviously picked up a few of the good points of PerlMonks. If it can build such a strong community, it'll be a great resource.