I've used all the freelancer type sites (elance, rentacoder) and have found oDesk.com to be the best. Primarily because you can get candidates to do technical

I've used all the freelancer type sites (elance, rentacoder) and have found oDesk.com to be the best. Primarily because you can get candidates to do technical tests (i.e. javascript tests) that I've found to be a fantastic predictor of success.