i think by now most of the people know about Git and Github. however, as i am still not very much hands-on vis-a-vis contributing in the open source community, i think this piece of information will be useful to others...
Git is an opensource version comtrol system developed by the same person who had created Linux. And using free version of Github, we can share our source code to the open source community.
For this one will just have to open an account at www.github.com, create his own repository. However, to push your source code to this github repository, one has to install Git in the local machine. The latest version of eclipse comes with EGit plugin, which is of great help to push the project from the eclipse workspace.
i think its a good step towards contributing in the open source community...
here are the step by step screenshots of how one can push his project into the GitHub directly from the eclipse workspace...