QuickerTek has released the US$89.95 nCard
(http://www.quickertek.com/products/nCard_2010.php) for use with a
MacBook, MacBook Pro or Mac mini with any wireless network. The
company says that users of the new nCard can expect wireless speeds
“that are the absolute fastest the wireless network can manage.”

To boost performance even further, this card can be upgraded with an
external antenna. That means even more distance from the wireless
access point. The nCard offers compatibility with all Apple AirPort
Base Stations, as well as Linksys, Belkin and virtually all other
wireless network hardware, including the “draft N” equipment.

This new nCard installs into the internal AirPort card slot. The
installation itself is no more complex than upgrading memory,
according to the folks at QuickerTek. It’s compatible with: all
2006-2009 models (white and black, no unibody) of MacBooks; all
2006-2008 (15, 17-inch models, no unibody) of MacBook Pros; and
06-early 2009 (no G4s, not most current models) of Mac minis.