SEOjunkie posted a thread at DigitalPoint Forums on a tool he built named the Google Ban Checker. The tool uses "typical checks like site: commands and it automatically checks the sites you link to to see if any of them are banned," according to SEOMoz.org.
It is also important to note that if you use Google Sitemaps, Google may also notify you of a penalty.
Forum discussion at DigitalPoint Forums.
