Thanks for the link!
Nevertheless, I was thinking less of a search box and more of a series of dropdown lists that act like filters… I would like the user to be able to select one or more values to each custom field key and then hit a ‘Search’ button. This search would then return only posts that match all of the selected values.
I think I’ll just have to build a php page with that functionality, maybe using that search function to power it, right?