T-Mobile has HotSpot @Home, Sprint has AIRAVE, and Verizon has its Wireless Network Extender, leaving just AT&T among the States" big four carriers without a launched WiFi or femtocell solution for extending signals into the home -- but it looks like that"s finally getting close to changing. We know that they"ve been in the process of trialing some units recently, and tipsters have observed that there"s now a pretty slick site launched on AT&T"s domain for its 3G MicroCell, an indication that they might be looking to go retail eventually.