I use an external Linksys 802.11g wireless card. Apple added support for these cards in June of 2003 in 10.2 (Jaguar) which was great, but less than pefect. You could experience kernel panics if you removed the card while the Mac was asleep, or inserted one after waking up the Mac.
I am happy to say that these issues appear to be solved with Panther. I have pulled the card with active network connections, plugged it back in and all was well. I have booted the machine without the card, plugged it in once the Finder finished loading and all worked flawlessly.
I have also tried several combinations of sleep/yank card/wake machine/insert card and have had everything work just peachy!