If you can find these lists, and if you can find a tool doing this -- Google can easily do the same. Do you want your first links to your brand new site in a competitive field to be ones that the search engines recognize as easy to get and where there are literally 500 other people writing comments on the same site with links back to their blog?
I'd suggest looking through the SEOmoz blog in the link building category for ideas about building valuable links instead. Takes more time, but is much better for your site.