I use getafreelancer. Sometimes you might have to try more than one programmer to get the work done though.
This minor disadvantage. Major disadvantage of getafreelancer is: If you have conflict with your coder/buyer - GAF can't help you: "According to our terms of service we do not arbitrate, but can give recommendations. If there's a dispute it should be solved between buyer and provider."
scriptlance sucks try the others I wouldnt recommend using that service there staff is dumb as a rock
There are plenty of sites where you write down what you need done and people will bid on the job and after bidding is over you pick the person you think will do the job well. I used to be a member of one but forget the link but try searching in google "Programmer Help Bidding" You should get a couple good results.