I have heard of a lot of people using this strategy. As long as you do a good enough job at rewriting the articles, I don't see anything wrong with this strategy. It should work quite well. If you do a half-assed job of rewriting the articles, you would be risking getting penalized for duplicate content. I'm not sure how Google determines what is duplicate content, but apparently even a small amount of duplicate content can get noticed.
you should post quality content on ezinearticles, goarticles, buzzle etc.. because they can generate a lot of traffic and aren't just backlinks. but the other 400 or so crappy ones, i used spun ones.
IMO article spinning is of no use ... plus i don't find it ethically correct to spam the world wide web with useless information just to get some more backlinks, most of them are of no use anyway.