This google code search is fun! It shows 728 results for c# IRepository interfaces used in OS projects.
Interested in NHibernate? This search shows 534 results for repositories that use NHibernate.
Actually, that might be a lie. I'm not sure how to make Google Code Search exclude matches that don't have all keywords present.
I wonder if it's worth including these kind of code results in the NHibernate Deep Grok search results?