I wonder if there is a way to play with the url submit string, you know, entering fields which don't have a UX selection. I use to do this with FB and Craigslist, leave the search criteria, and change the locale. In facebook, it was more the search string copy paste to groups(this was before marketplace). These hacks should come in handy if someone can hunt them down. Espeially the geo-tagging and the income-bracket (I am sure there is an income-bracket criteria in their big "benevolent" database... lol