As expected, today AT&T announced the addition of the Palm Centro to its lineup of smartphones. Unlike the Sprint's red and black models, AT&T's version comes in white and features lime green buttons. And while it carries the same affordable $99 price tag (with a two-year contract and after rebates and discounts), you do lose the 3G speeds and have to settle for ho-hum EDGE. However, it does support the carrier's push-to-talk service and AT&T Music. Otherwise, the GSM version of the petite Palm smartphone is very much like its CDMA cousin. You get a 1.3-megapixel camera, Bluetooth 1.2, preloaded instant messaging clients, and push e-mail capabilities with support for Microsoft Exchange ActiveSync, Good Mobile Messaging, and Xpress Mail. You can get your hands on the white-hot AT&T Palm Centro starting today.