Yeah, I did toastmasters for about a year after I stopped doing speech therapy after my stroke, to give me some kind of structure for making up the gaps between what speech therapy treats (basically, going from anomic aphasia to baseline) and my actual desired performance target. (I stopped doing it when I got good enough that I could confidently start doing community theatre again.)

Results vary enormously, depending on which group you join, but the basic structure of "talk in public, get feedback, talk some more" works pretty well. The quality of the feedback is variable, natch. Still, if you're looking for a structured environment to practice public speaking in, I recommend it.