Power over Ethernet AirPort Extreme Base Station
Apple is now offering an AirPort Extreme Base Station that uses Power over Ethernet (802.3af) which allows you to forego running AC power to a base station, and instead "injecting" it over the same cable used for Ethernet. It's a growing technology for access points, often located in places where it's expensive or impossible to run AC power. Even better, existing Ethernet wiring can often handle the power injection. The PoE base station has no modem but does include an external antenna connection and retails for $250.