If you have a module you would like to contribute, please register on this site, and then send me an email with the user name you setup. I’ll set you up with the privileges you need to post your module.
If you don’t have a module, but you still want to to help out, you can! You can help by testing the modules that exist. You can help write documentation and also spread the word by doing blog posts and ScreenCasts about your favorite modules.