I would go for a wireless lan card, not wired. For a PDA in my opinion wired lan connections are kind of silly. Not that there's no use, it just against the whole portable notion of a PDA. That said, here's a deal at CompUSA for a Netgear CF wireless card -
link. The price is $70 ($10 instant rebate for $80 normal price) and there's a $40 rebate from Netgear (not CompUSA), bringing it to $30
AR. Valid through 5/10 (Saturday). $5 delivery if you order online, but better to pick it up in the store if you can.