Foursquare as a dating companion?
It's not such a far-fetched idea. If MySpace and Facebook and even Twitter can be used by people to find dates among their common social networks, then Foursquare (fondly known as a stalking tool) can be used as an anti-stalking tool. This could give a whole new meaning to the "Player Please" badge.
If you go on a date with someone you barely know -- whether you meet him or her online or out and about is irrelevant -- common safety practice tells you to let your friends know where you are going, who you are going to be with, and that you got home safely. With Foursquare, you already have a built-in network of friends who, creepy or not, are watching your every move. So, for instance, one could check in at Local Pub and send a shout that says, "Here with Bob Smith" or if you're paranoid, "Here with a blind date. If I disappear, his name is Bob Smith." This is slightly more private than posting to your Twitter or Facebook feeds, yet let's enough people know where you are and what you are doing should something go awry. And if you're super paranoid, you can even show your date and say, "SEE. People KNOW where I am at..." but if you do that, you likely should not be dating in the first place.
Of course, this is a passive approach. Not everyone pays attention to their Foursquare feeds or gets pinged with every check in. Not to mention, not everyone has created a location for his or her home, so that person would have to either shout that he or she were home safely, or make friends wonder if it was a *really* good date or if something bad happened.
It would be interesting to see if there is a way that dating sites such as Match.com, eHarmony and Chemistry.com could partner with Foursquare, even if it's just a marketing partnership. "Tell your friends where you will be" and link to the Foursquare app, etc. It might sound a bit quirky, but it's an opportunity for Foursquare to tap into a whole new user base of online folks looking to socialize -- and find love.