wheel - 6:19 pm on Oct 25, 2010 (gmt 0)
We've all got a good amount. Scrapers and the like, you'll get backlinks from all manner of garbage sites over time.
Ignore them, they shouldn't hurt you. It's part of a natural backlink profile.
If you want them gone, you'll have to contact the site owners and start begging. Since many of the sites will probably be sites that scrape and publish automatically, I would expect you will have little to no success in asking for a link removal.