Broadcom 43xx wireless on FreeBSD 7

FreeBSD is one of the most awesome UNIX-like operating systems available. It even works on laptops, just not very well on mine. I own an Acer Extensa 5220, a major el-cheapo piece of kit containing a Broadcom 4311 wireless LAN card. These same cards are known to appear in Dell laptops as 1390 cards. Finally, after a week of fiddling, I got this card to work natively on FreeBSD 7.