That’s exactly the type of thing I was looking for.
Last night I implemented something similar using a google custom search but it’s not as good as a totally “local” solution. You can try it on my site now.
But I’ll implement this solution and replace what I have this weekend. Thank you.
ps: all the examples in my OP were pulled from my analytics. The most interesting ones for me are people typing something else in the middle of the URL. Oops!