You would get a PDA with a card slot and add it. Today we still don't put 802.11g into PDAs since the battery time would plummet ever further.
Shop and wait?
I'm disappointed that I can't find a PDA that does g and not b only. Many WAPs will lock out b, because it slows everybody down to b (11Mbps) when a b walks into a g (50+Mbps) space. Should I wait another six months to buy a PDA in order to get "g" wireless?