Odesk.com. I love shopping for developers! Founded in 2003, oDesk allows you to hire people and find gigs.Odesk is the largest online workplace, where you can hire, manage, and pay a talented workforce of on-demand professionals. You can find web developers, Ruby on Rails developers, open social developers, Joomla developers, Software engineers, someone to build you a website or fix code. I recently used odesk to have someone build me both an iPhone and an android application. You can also set your own price.
Check out the video below to see how odesk can work for you.