Even though Google killed Dodgeball, Dennis Crowley reassured the socially inept that they'd still be able to find their friends at bars with his newly launched Foursquare. One problem: it may not be his.

Foursquare bears an unmistakable resemblance to Dodgeball, a cell-phone-based friend-finding service Crowley launched in 2004 and sold to Google in 2005 for an estimated $40 million. Crowley worked at Google for two years afterwards. And his former employer may be getting ready to take legal action, if a tipster is right:

The GOOG has reason to believe that the recently launched location-based service startup Foursquare went live using server code that originally powered Dodgeball. A cease and desist order might be sent out to the service as early as this week. An engineer named Harry could also face some additional discipline.

Dodgeball worked by having users check in via text message when they arrived at a location like a bar or restaurant, and broadcast the user's whereabouts to friends — a precursor of Twitter, in some ways, but focused on people's whereabouts. Google ended up killing Dodgeball (a smart move) but launching a similar service called Google Latitude.

Foursquare's added twist: It turns hanging out with friends into an interactive game, with users racking up points for going out. It also has some au courant features, like an iPhone app and integration with Twitter — the kind of thing any Web app needs to be hip these days. But according to an engineer familiar with Foursquare, its back end appears to bear a strong resemblance to Dodgeball's.

Crowley quit Google in 2007, complaining that Google had stifled Dodgeball. One rumor floating around has it that he tried to buy it back from Google, without success. So it makes sense that he would want to relaunch it, and might feel entitled to use the code he wrote, since Google abandoned it.

It also makes sense that he would have help from the inside. The "Harry" the tipster mentioned is almost certainly Harry Heyman, a Google engineer. Heyman was caught by surprise by his employer's announcement of Dodgeball's shutdown. In January, Heyman wrote on his LiveJournal:

Don't fret too much about not having a tool like this to use when dodgeball gets turned off. Like you, I'm pretty unimpressed with most of the other current offerings, but I know of a couple soon-to-be-released things in the works. Keep an eye out, and we'll all find a new home that suits our needs just fine.

But that's the hitch: Google already paid Crowley for the code, and even though it's not being used, Google's lawyers would reasonably want to disabuse startup founders of the notion that they can sell their startup and have it too.

Crowley and Heyman have not yet responded to emails asking for their side of the story. A Google spokeman promised to look into the matter but has not yet offered comment.

Now would be the perfect time to strike, with Crowley at the South By Southwest Interactive conference in Austin, Texas, surrounded by his friends and fans, many of whom have signed up for Foursquare.