Interesting article - lots of good forums in there that I wasn't aware of. I agree completely that it's bad form to request free work from freelancers. If you absolutely need some trial work done to evaluate them as a developer, give them a few smaller paid projects to complete.
One thing I would add is that the marketplace is full of skilled overseas developers. At our company, we have a great JS developer who does contract work for us from India. Her work is top notch, but communication is often difficult. If considering workers abroad, understand their availability, communication skills, and always prepare specific requirements.
