You’ll see our first pass at this in foursquare 3.0′s new “Explore” tab. The idea is pretty simple: tell us what you’re looking for and we’ll help you find something nearby. The suggestions are based on a little bit of everything – the places you’ve been, the places your friends have visited, your loyalty to your favorite places, the categories and types of places you gravitate towards, what’s popular with other users, the day of the week, places with great tips, the time of day, and so on.
(Full Story: Foursquare 3.0)