So, a video game that rewards being adventurous and outgoing in, you know, real life?

Mr. Crowley and his partner Naveen Selvadurai introduced their Foursquare mobile phone application to more than 500 Meetup members at the F.I.T. Haft Audiorium on 27th Street. With Foursquare, users can download a mobile application that will let their friends know exactly where they are (by text message, Twitter and on maps, too!), and also find fun, new things to do in spots in their immediate location--"like, try this specific beer at Spitzer's Corner," Mr. Selvadurai explained. Users can create their own tips and track all the cool things they've done (in a "Top 12") and the things they want to do (in a "To Do" list).

But it's also a nightlife game. Users rack up points based on how many new places they visit, how many stops they've made in one night and who else has been there. You become a "mayor" of a hot spot if you're there often. Mr. Crowley used an example of Spitzer's Corner, where Nate Westheimer, N.Y.T.M.'s head organizer, hangs out. "If you check in there one more time than Nate, then you get a message, 'Oh you stole the title of mayor from Nate,'" Mr. Crowley told the Observer in a phone interview this morning. "People get kind of competitve about this." There's a "Leaderboard" which lists the most adventurous users with the most points.

But, Mr. Crowley said, "If you keep doing the same things over and over again, if you go to the same place several times a week, your points get taken away."

Eventually, you can acquire electronic badges for your achievements. "It's almost like X-Box Live achievements, but for real-life, social life, nightlife," Mr. Crowley explained. "You start to earn these badges as you do interesting things in the city." Go out four nights in a row and receive a "bender" badge. There's a "Brooklyn 4 Life" badge for those who bar crawl in that borough. If you check out a few of the 25 spots tagged as a "douchebags" hangouts around the city, you'll get a "douchebag" badge for your bravery. There are currently 16 badges, "but the idea is to have like 300 of them, with users creating badges for each other," Mr. Crowley said.

Foursquare also built in user-generated tips for cool things to do in the city, like trying to certain kind of beer at a bar or checking out an underground club. "We wanted things that were really actionable that then people could do," Mr. Crowley told the Observer. "If you have a friend coming from out of town, and they say, 'Oh, I'm going to be here for the weekend,' they can look up, like, these are the ten best things to do on the Lower East Side."

Of course they are just in time to test it out at SXSW, the music, technology and culture fest in Austin, Texas (where Dodgeball thrived in 2006).

There are, of course, other applications, like Google Latitude, that allow users to see where their friends are on their mobile phones. But "it just seems really boring," Mr. Crowley told the Observer. "There's no personality to the service, it takes all the fun out of it. How do you explicitly put all the fun back into it?"

Foursquare is Mr. Crowley's second act in the mobile social networking application world. A 2004 graduate , and now adjunct professor, at NYU's Interactive Telecommunications Program, Mr. Crowley was the co-founder of Dodgeball, a service that let its users share their location with friends via text messages. He created the service in April 2004, along with his business partner and NYU classmate Alex Rainert, and Google bought Dodgeball in May 2005. Mr. Crowley and Mr. Rainert resigned from their Google duties in April 2007, and Google decided to discontinue the obscure, yet much-beloved service in January this year, officially shutting it down last Friday. Dodgeball faithfuls gathered for a final good bye to the service at Bowery Electric on March 6.

"I'm interested in starting over again," Mr. Crowley told the Observer. "Dodgeball got a little bit of a bad rep because there was such a hardcore group of Dodgeball users. For better or for worse, people stereotyped us for that."

Foursquare is a amped-up version of Dodgeball that, appropriately, can be played like a game. But you can't play just yet. Mr. Crowley and Mr. Selvadurai are waiting for approval from Apple to sell the iPhone application in the App Store, but plan to make the service available on all kinds of mobile platforms, including BlackBerrys. Currently the service is in private beta.

"The principle of a lot of this stuff is just to encourage people to stop going to the same places, start doing more interesting things," Mr. Crowley said.

"There's a lot of people playing in this mobile social space, and when you click with these tools, this feels like an episode of Seinfeld, like it's a scene you see over and over again--the same people at the same places all the time. And we're looking for ways we can use these social mobile tools to kind of encourage people to do things they wouldn't normally do."