This is an old revision of the document!
b43 is the new driver for wireless cards with Broadcom chipsets. People have had limited success up to this point. For now, search the Forum for “b43” to get the most up-to-date information.
There is a patch by SuD which dramatically improves the injection speed (Kernel 184.108.40.206 or higher needed):
Also see this thread for more information.
To use the b43 driver, make sure you do:
ifconfig wlan0 down iwconfig wlan0 mode monitor ifconfig wlan0 up