Most of the legitimate jobs I've heard about or had acquaintances work for were in the medical, legal, and IT fields.
As someone in the other thread mentioned, apparently medical transcription is still in the growing/stable phase and there are people needing the service. Take some certification to get qualified and then you just type medical records until your eyes bleed.
Legal is pretty much the same thing, contact some attorneys and see if they need someone to type case files for them at a reasonable cost, don't know how this will pan out but have heard that it is a possibility.
IT is web development from home, had a friend that did it on a free-lance and corporate level, but he had a 2 year degree and pretty lax company.