I recently reorganized my home wireless network a bit, and the AP that I had been using connected to my Linux box stopped working. I wanted to replace it with an internal card but it's annoyingly difficult to find a wifi card that works well with Linux.
Various chipsets are supported with Free drivers but the trouble is that you can't buy a card by chipset - you have to pick a card, research it to try to figure out what the chipset is and then see if it is supported. Even then there's no guarantee because many manufacturers make several completely different cards with different chipsets and give them the same model number (which kind of defeats the point of a model number if you ask me). And the online shopping places don't tell you the revision number of the card you're buying.
Eventually I gave up trying to find one with Free drivers and settled on this one which people seemed to be having success with. Indeed Ubuntu 8.04 recognized it straight away and connected to my network. Still, it's annoying that it's so difficult to buy a card for which Free drivers exist.