Agreed that vWorker is good, due to the business model.
They broker and facilitate the transaction between work buyer and worker without costing either party money up front. vWorker only collects if a transaction is initiated and completed, or under special project type circumstances (cancellations mid-way, dispute resolution, etc.)
The worker doesn't have to pay money to compete for a project, they simply have to demonstrate proof they can handle the job & establish a good dialog with the buyer.
Other virtual work sites charge workers to even bid, and then rationalize it as some sort of quality control barrier to entry, but it really discourages many, many potential bidders and reduces the talent pool.
Realistically, for every fly-by-night worker with zero feedback on a freelance project site, there are just as many unscrupulous low-balling buyers looking for unrealistic returns. vWorker's model ensures that neither party pays unless both parties actually do business, and that's very fair.
Source: seven years' experience and 50+ successful 10-rated projects as both a buyer and coder on vCoder.com.