We manage an nushackers git repository on github.com. It contains things like source code of this web site and source code of our hackerschool website. Free feel to clone/fork any of those or, even better, send us pull requests!
If you are a NUS student/staff, we also have a repository for your projects: http://code.nushackers.org - use it to showcase your work! After doing so, you are welcome to contact us if you want us to maintain and publicize your code!