Just found someone (birchTree, hi guys!) out there wondering how they might go about indexing a SQL Server database with SharePoint.  

Using SPS to search 3rd party SQL databases.

I have often found customers posing the same question, and in a number of cases we were easily able to achieve just this using the following technique:

http://blogs.msdn.com/danielmcpherson/archive/2004/12/20/327398.aspx