Love it? Or Hate it? Foursquare just announced a new feature that could be embraced by users who are tired of checking in—and, eventually, by advertisers. As described in a company blog post, Foursquare’s Radar turns the app into a location alert system, even before you’ve checked in somewhere or opened the app. So you can get alerts when a group of friends has checked in nearby, or when you’re near a location that’s on your To-Do List. Click here to read the full story adweek.com