Today I came across shapado.com – a StackExchange-like open source system running on ruby and mongodb. It took a couple clicks and a few keystroke, and I had http://jobs.shapado.com/ setup and running for free. It was a quasi joke at first, but I figured it might be helpful to get this up and running. So, if you have any jobs to post, or would like to request work, please post away
You can also set up your own, or download the source from the seemingly unreliable gitorious.
You can also help out by voting this up on reddit