I've used rentacoder and almost every other online outsourcing company as a coder as well as an employer for over five years. My personal experience has been that it if you don't know your way around technically, there is good chances you will be taken rounds by most coders--or have a torturous time explaining your needs to the coder.

I continue to use rentacoder etc. extensively. Yet best way I can put it is that most coders on such sites cannot be replaced with technical knowledge on your end. The good coders are great for getting x, y, z coded according to detailed specs but very hard in planning those x, y, z.

Planning is 80% of the hard part in programming.

Exactly.

That is why I have a tough time recommending even people on campus that know little about website design to goto RAC or elance to find a designer or a coder. I've seen it from both perspectives. From the lowball bidding most people on such sites do, as a designer I don't really expect a $100 website to take me a month and for me to think about it all day. So if you don't know exactly what you want you'll get some very average work.

Also, take a look at www.odesk.com.