Microsoft {Open Source} Heroes Happen Here
If just happen that you would like to contribute to Open Source Community and you are developing solutions on Microsoft Platform - this is site for you: http://www.microsoft.com/opensource/heroes/default.mspx
At first I was a little bit shocked to find this URL in Google, searching for Heroes Happen Here Community Launch dedicated web sites, but when I looked more carefully - it is really Microsoft web portal with information about:
1. Open Source
2. CodePlex
3. Visual Studio Express
4. Shared Source Initiative
5. Port 25
6. etc..