If you're living in a location so remote that even standard cellular repeaters can't salvage your cellphone connection, the UbiCell from Samsung should be the device for you. The UbiCell connects via 10/100 Ethernet through your cable connection and pipes WCDMA/HSDPA through the internet to your provider, which routes to whoever you're calling normally. The end result for you is that now you have a cellular connection in your home where there was none before.
Samsung's working on provider support—the Ubi is going to be distributed through SpriVeriAT&TMo whenever they work out an appropriate deal—similar to the way that T-Mobile's VoIP service is being rolled out soon. The thing does look nice, which is probably secondary to its ability to let you use your cell at home. We'll update when there's word from a provider.