http://en.wikipedia.org/wiki/Ephedrine
First I recall hearing about it was the mid-80s book Life Extension Weight Loss Program from megavitamin proponents Durk Pearson and Sandy Shaw. So this has been known of for a while.
It was also thought to be debunked because "adult humans don't have brown fat" - which, as this article makes clear, is more "don't have much". But better imaging techniques have brought brown-fat thermogenesis back around.
If you're trying to do this with vitamin/herbal supplements, I think the current trend is to use "bitter orange" instead of ephedrine. I find it's not very effective for me, but I wasn't a fan of ephedrine either.