I implemented something very similar in perl a few weeks back for my user interfaces project; I wrote a desktop search client that would take a query from the user and score results based on how many and how well it matches a series of different interpretations of the query (fuzzy was one of them).
I too am really amazed this isn't more prevalent as it is so easy to do, after discovering the vim ctrl-p [1] plugin I rarely go a day without using it.