ProPublica just released a search tool for nonprofit tax records:
The possibilities are nearly limitless. You can search for the names or addresses of independent contractors that made more than $100,000 from a nonprofit, you can search for addresses, keywords in mission statements or descriptions of accomplishments. You can even use advanced search operators, so for instance you can find any filing that mentions either “The New York Times,” “nytimes” or “nytimes.com” in one search.
Have a go here.