I normally don't like it when I see someone post an alternative rather than addressing the exact fix, but in the case of Broadcom I just have to. Wifi support has improved rather dramatically in the last few years so this alternative fix may not have the massive bang for the buck that it used to but it is most certainly cost-effective if you value your time and have better things to do than mess with some manufacturers' obstinacy.
A few years ago when just sick of messing with the wifi mess, and dealing with more than one alternative OpSys lacking said support, I spent ~$30 US and got a pocket Wireless Access Point. Since NICs are very well supported everywhere and since the (or many) WAPs connect via ethernet, it instantly solved ALL my wifi issues and then some, since it can be a great mini-router on business trips, LAN parties, etc.
If this isn't for you then please just ignore this, but they really are worth at least checking out. They are vastly more sophisticated today and direct and simple to implement.