I am trying out his new site that one of my former grad school professors recommended to me. It is called Livemocha. In addition to having a pretty kick-ass name, it also seems to have quite a lot of free perks for its members. There is a three-day free trial of everything, but I think a lot of the basic services and beginning lessons are free.
The best part about this site is the fact that you can submit writing or audio clips of yourself speaking, and honest-to-god, real people read or listen to your submission, rate it, and give you helpful suggestions. At my fingertips are hundreds, perhaps thousands, of native speakers of my target language (in this case, French), but I could also get help with Spanish, too, I suppose.
AAAAAAAAAND... If I am helpful and review submissions by people who are learning English, I earn points towards a "teacher score" which can help me get more free lessons if I rack up enough of them. I will have to report more on this as I test it out.
The only downside right now is that I cannot figure out how to record anything. My computer and Flash and this website seem to all be speaking different languages.