Today two Greek entrepreneurs launched a new iPhone app called 4sqwifi, which uses the Foursquare API to find locations nearby that offer free WiFi, along with the WiFi's passwords. The app gathers nearby venues, searching for keywords like "wifi" or "password," and then displays only those venues. There are also a small percentage of false-positive tips that might pop up, like "password for men's toilet." But if you can deal with (read: laugh, man!) this margin of error, then you'll enjoy this app. To use the 4sqwifi app, you must have a Foursquare username. If you've resisted using Foursquare for some time, this might just be the app that changes your mind.

4sqwifi works in the opposite way that Yelp does. Whereas you type in your zip code and Yelp tells you about cafes nearby (and you can do an emphasis on free WiFi), 4sqwifi saves you that extra step by just targeting free WiFi connections. "4sqwifi is mainly about social location awareness in an everyday's life-hack thingy," says co-creator Apostolos Papadopoulous, who worked on 4sqwifi with Giannis Poulakas. "Tips are user-generated and the best thing is that 4sqwifi works immediately with and in Foursquare's community - worldwide."

There are no plans for releasing a similar app Gowalla, which feels increasingly game-ier.

This app gives users even more incentive for using Foursquare, which recently updated its website to better personalize places nearby.