An iPhone Carrier Settings Update was pushed out by iTunes recently. What's in it? Among carrier images for some new carriers like the UAE's Emirates (iPhone should be coming to them in a week or so), carrier images for AT&T's MicroCell (site under maintenance at time of story writing) service are now included. MicroCell is essentially a tiny cell tower which gets 3G signal from broadband internet.
(image from MobileCrunch)
Here's AT&T's description of MicroCell:
AT&T 3G MicroCell acts like a mini cellular tower in your home or small business environment. It connects to AT&T's network via your existing broadband internet service (such as DSL or cable) and is designed to support up to 10 3G capable wireless phones in a home or small business setting. With AT&T 3G MicroCell, you receive improved cellular signal performance for both voice calls and cellular data applications, like picture messaging and surfing the web for up to 4 simultaneous users.
Commercial devices for extending your cell reception can often run $300-600, so neither of these prices are too bad. We'll see how AT&T competes.