The US$89.95 Quicky Jr II comes with an easily-installed USB driver that lets it work with your 802.11n/g/b networks, including those that are powered by an AirPort Extreme Base Station. While I'm usually dubious of any device that claims to increase wireless range unless it is pitched by the late, great Billy Mays, the Quicky Jr II appears to be just what it says it is; a powered USB Wi-Fi antenna. In theory the larger antenna size and a built-in USB-powered amplifier could help boost the signal, then route it to your AirPort circuitry.
Rather than speculate on how well devices like this work, I'd like to ask our readers. Do you have any experience with this or similar products? Do they work as advertised? TUAW wants to know.