When it comes to 802.11b I have the following comments:
Linksys: I bought their printserver/router/802 box and it SUCKED. Like SUCKED. Their tech support are complete idiots and overall using the product was a nightmare. I returned it and will not buy another Linksys product in the future. I had been a fan of their wired routers in the past so this really disappointed me.
SMC: The replacement ps/router/802 box I got is an SMC. It has been fantastic. I bought it off compuplus.com, who, by the way, is a pretty kickass retailer.
Lucent & 3Com: For your computer/laptop, get either a Lucent ORiNOCO card or a 3Com. These are the de facto best cards around. The 3Com stuff is the best, but of course it is $$$$. Get an ORiNOCO and you will be happy.
PCMCIA & USB/PCI: All my experience so far has been with laptops using PCMCIA cards. I have a PCI card coming later this week and will let you know what I think. For a desktop you can get a PCI card, a PCI-PCMCIA adapter and PCMCIA card, or USB solution. Keep in mind that usb might not give you maximum bandwidth.