The Hack of the Week Series highlights a new hackathon programming project each week.







Google engineer Mihai Parparita met his wife during their junior year of college. But at some point, it occurred to them that they had actually taken a class together two years prior to that without introducing themselves.

It took the couple years of conversation to discover this coincidence, but Parparita recently created a way for other couples — or friends and people who just met — to plot their past intersections. A clever app he put together at a Foursquare Hackathon in San Francisco compares two people's checkin history and shows them when they've been in the same room. The app is called Intersquares.

"It’s a way of figuring [out where you saw someone before you met them] but also a good way to relive memories with friends," he says. "For people who were using Foursquare when they started dating, it's a nice confirmation of their first date."

To use Intersquares, users hook up their Foursquare accounts and send a link to whomever they want to compare checkins with. As soon as that person links his or her account, voilà, out spits a list of common checkins.

Intersquares was picked as a Foursquare global hackathon finalist out of 90 entries that were created at local hackathons in New York, San Francisco, Tokyo and Paris. Winners were determined by Foursquare employees and online votes.

In addition to a giant inflatable shark, Parparita won the honor of his app becoming a part of the Foursquare badge system. People who connect their profile to Intersquares or the other three finalist hacks will get a "Platformer" badge.

"It’s not about money, it’s about the world glory," he says.

Image courtesy of iStockphoto, gehringj