I can see the potential with Foursquare, don't get me wrong - but I do think at the moment it's missing a few vital ingredients. One of them being, err, "fun" - but this Monopoly tie-in could be just the trick.
Handshake magazine spoke with Jonathan Crowley (I'm guessing he's a relation to founder Dennis Crowley), who mentioned the Monopoly app which they're working on at the moment. As it hasn't been formally announced yet, it's not known whether Foursquare's actually inked a deal with Hasbro for name-rights. It could just be a "Monopoly-style" game, where you and a bunch of friends compete to log into as many venues on a list as possible, with Crowley only mentioning the board-game name to better explain it.
Crowley says in the video that "Everyone has fake cash of £3000 or so, and when you check into a venue, if nobody has checked in before, you can buy it," and as the real Monopoly game is wont to do, you can then charge rent to those who dare check into that venue. And then throw all the fake money into the air and mess up all the hotels, houses and gamepieces when you lose. Not that I do that. Ahem.
Also mentioned in the video is the possibility of hookers checking into the corners they work, and offering discounts to those that "frequent" the "corners". I bet Apple would just love that. [Handshake via Electricpig]