Well, at least they're honest about what they do. A new iPhone app called Stalqer helps you locate your friends, even if they're not signed up for your favorite location-based service - like Google Latitude, Foursquare or Loopt. Users who opt-in to Stalqer ping the service with their location every time their phones check for email, which gives nearly real-time updates on the iPhone (which can't keep an application like FourSquare open in the background). That part is only slightly creepy. The creepier part is that Stalqer tracks friends who aren't even using the service.

By pulling info from friends' Facebook locations, the app can give you a general idea of where people are. It can't yet read status messages and wall posts to look for location info, but it reported does a fair good job of finding people without that capability. The app does have SOME privacy features: it won't let you track people who you haven't added as contacts in your phone's address book. That's pretty easy to get around, though: just add the person you're looking for.

As far as what information you share through Stalqer, you can control how precisely you're located and also turn reporting on and off. If you only want to show some friends which city you're in, and not the street address, you can create a group and change your privacy settings to allow for that. It sounds like Stalqer is trying to build the kind of app that everyone wishes exists, but nobody admits they want. Where do I sign up?

[via CNET]

UPDATE: To clarify, following someone on Stalqer requires you to be Facebook friends with that person, which is something they'd have to approve.