Just in case I’m not the last person on earth to hear about it, stackoverflow.com is one of the most useful programming sites on the internet. If works a lot like Yahoo! Answers, where questions are asked, answers are posted by humans, and the answers are voted on for their effectiveness. Unlike Yahoo! Answers, the questions are less “How is babby formed?” and more of the “How do I get this *bleep*ing code to work?”. All manner of programming subjects are tagged and categorized, from ESRI to fortran.
Most importantly, by answering questions on the site, freelancers can show off their skills or keep certain areas of expertise fresh . Unlike posting on programming forums and blogs, stackoverflow has the potential to reach more people from multiple disciplines. If demand for one technology goes down, clients and recruiters don’t have to go look far to see what else you are capable of.