Thanks for the info – the links are really helpful!
I was thinking of checking the referrer, if present, and if Google/Yahoo/Bing, grabbing the search terms and query. For yahoo, the terms are in the p= parameter separated by a space. In Google’s referrer, it’s the q= separated by a + character. Not sure about Bing but it’s easy to find out. I know there are plug-ins that do this – maybe one has a short code I can use.
If not, see if it came from my blog, and grab the permalink, parse it first on the “/” characters, then the “-” for the permalink terms, and query.
Finally, default to some “featured” posts/pages/info and a search form. This is pretty easy, so that’s the first thing to do.
If anyone else has any other ideas, please feel free to share!