Hi, this is Nicole from vWorker.com (formerly known as Rentacoder.com).
vWorker has a requirements wizard and a project posting wizard to help build a project that's easy for workers to understand. It also provides a search engine so that you can find and work with specific workers based on geographic location and/or language. Used together, both the search engine and requirements/project posting wizard eliminate communication problems as suggested by nicomp.
If you have any questions, feel free to call in to talk to a facilitator, or send email through the site's feedback form.