Not that I know of. SharePoint search is not always the best anyway.

You could create a custom list, but this would need to be maintained.

I store all of my forms in a SQL server with the Database Accelerator
package from http://www.qdabra.com which makes querying the available
templates and the documents very simple.

I guess it will be easy depending on your programming experience. :) You
should be able to use the SharePoint object model to retrieve all of the site
collections on your SharePoint server, the sites of all of those site
collections, the libraries (=lists) of all those sites, the content types of
all of those libraries, and finally the document templates of all of those
content types. There are plenty of examples in the SharePoint SDK on how to
navigate the object model to retrieve such information.
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S.Y.M. Wong-A-Ton