Google has been adding features to its maps at a fast and furious pace. Yesterday, it was terrain and wiki-style collaboration for its Web-based maps. Today, it updated its mobile maps to pinpoint your locations by triangulating between cell towers (or if you have GPS on your phone, it uses that, but only 15 percent of phones sold this year even support GPS). I just downloaded the My Location app to my Blackberry (sans GPS), and it pinpointed me to within a block of my location in Manhattan. I’m a little blinking blue dot on the map. Although, if I move around the office, it picks up another set of cell towers and puts me nearly six blocks away. Oh, wait, now it has me nearly perfectly on the right block. Now it has me around the corner again. At least it’s got the right neighborhood—and Manhattan does have a lot of cell towers.

Here’s a video explaining how it works: