I always carry around a wireless USB adapter in my "toolkit." My current adapter is only 802.11g and has seen better days. The male USB connecter us getting loose and Im afraid its one bad yank away from being broken.
So I was thinking of replacing it with an 802.11n model, but Im curious as to which model/chipset is supported out of the box by the most operating systems. Naturally Windows needs to be supported, as well as Mac OS X, and as many Linux distros as possible. BSD would be nice as well.