I discovered this brief ‘howto’ (on twitter, of course) from @the_api_book via @ginatrapani.
Head over to google.com and enter the search phrase:
site:twitter.com/*/favourites your_username
where your_username is your twitter user name.
For example, this search returns the results for all of the folks who have favorited a tweet made by the user @lifehacker, and which tweet it was that was favorited.
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