Good answers, I am inclined to think I will be looking for contractors / project workers for GIS, so this is very interesting.
At the moment I am developing a web project (no GIS yet) and think my experience with Elance is worth noting.
Elance certainly has a number of workers available. There is an accreditation system and access to profiles, past jobs etc. However I have had some very disappointing connections and I get the impression there is a great depth of workers there who grossly overstate their skills. I engaged one "company" who turned out to be a one man band who had a few good ideas but was obviously overwhelmed with what had to be done in the time, he never advised me of delays and it was very frustrating for us both.
Another guy is nearly completed a project and has just revealed he has only used the code package in question once before, which would explain why he is three weeks overdue on his component.
I am very wary now. Rather than have Elance purport to have vetted the candidates for me (or provided a framework) I would rather take my chances on anonymous contacts and vet them from scratch.
In fact the most successful group to date had a plain jane web site, the only professional linkage was that they had got noted as being able to provide professional support to a database package. They are going well.
Another point is that the profile of contractors who struggle...... are recent graduates who go on their own and take on tasks of which they have little comprehension. Their fault is that they are young. These guys are hurting themselves (as well as the client) and they would be better off in a team learning some work discipline. It is hard to stay on track and get things done (google David Seah....) and freelancing is the pointy end of the stick.
Says me doodling on this ramble....