Ha. If you get it working, I imagine something like
<forum url>/?action=search;LMSTFY;q=<query_word1+query_word2+...>
HLMSTFY would stand for Let Me Search That For You, of course.
I've not looked in a long time, but if SMF licensing allows for donation requests for plugins you author, I'd bet you'd get some.
Though Google turned up the exact same thing he was looking for in it's top two results from our forums, we'd like to have folks just use our search.