You know I don’t like it when you go there, Dave

Gosh, there’s no way this could turn out to be a bad idea: Google Latitude, the application that lets you stalk your friends via mobile phone (and vice versa, because after all, it’s only fair), just switched on a couple of new capabilities. Location History remembers where you’ve been, and Location Alerts let your friends know when you’re nearby. Both sides need to opt in, of course. Here’s the special part: Location History and Location Alerts work in tandem, and your friends only get alerted when you’re at a nearby place the ghosts in the machine deem to be “unusual” — that is, out of your historical profile — or if you’re at a usual place at an unusual time. So: Let’s say you habitually spend between 5 and 7 pm at that strip club out by the airport.  Your friend Sal, who lives in a basement apartment just past the end of Runway 9E, won’t be alerted to your presence there unless you go out of profile and suddenly show up at 9:30. Which would be bad for you and good for Sal, because you’ve owed him that yard and a half for like a year now and he’s gotten so tweaked on meth in the meantime that he’d probably call up his biker friends and roll out there and stomp you! So remember, keep your phone switched on and stay right there by the service bar where he can find you. And remember to thank your friends at Google.