For those of us with older Macs that only have airport 80211b cards inside there is another way to get to 802.11g speeds that requires no drivers or compromises in security. Use an Ethernet bridge device. This basically brings an Ethernet port to you wirelessly. You will have to use have an Ethernet port on your Mac but unless your Mac is really old you should have that. Since you configure the device via a web browser and it uses your Ethernet port you need no extra drivers, just configure your Ethernet port and you are good to go.

They are more expensive than USB adapters but starting at around 70 bucks that are not that badly priced. Some like the buffalo have several Ethernet ports so a single bridge can connect several computers, printers, whatever has a port and is within reach of an Ethernet cable from the bridge.