Today, I purchased and installed the Edimax EW-7316Ug wireless 802.11b/g USB Adapter. While I usually approach the purchase of hardware for Linux - especially for non-mainstream products - with a certain degree of trepidation, I was heartened to note during my pre-purchase exercise that the Edimax page specifically mentioned Linux compatibility and even provided a source code download. How rare is that?!
The device is inexpensive and looks very much like an overly squat thumb-drive and is used similarly. As soon as I plugged it in, my Kubuntu 9.04 Jaunty Jackalope installation detected it and the network management widget offered me a list of available networks. No driver compilations, installation wizards, restricted driver dialogues ... nada. It was an absolute breeze and props to Edimax for being one of the good guys!
I know I'm just being snarky, but, Windows (XP SP3) required me to pop in the installation CD and run through an installation wizard and a reboot before I could get the card working :P
I'll see how things go with FreeBSD in a couple of days time.