I haven't tried this out yet, but I saw this on a blog:
http://www.downloadsquad.com/2006/05/11/is-your-web-site-blacklisted-by-google/
It's a free Windows app that will take a list of web sites and see if they're indexed by Google. On top of that, it will crawl your site(s) and check all of your outbound links to see if you're linking to any sites banned by Google, which can damage your pagerank.
http://www.downloadsquad.com/2006/05/11/is-your-web-site-blacklisted-by-google/