you need a wireless router and a wireless card (PCI) if your laptop doesn't have the built in wireless modem.
I have recently bought a refurbished dell c640 with 1.8GHz, 256MB, and 30GB. I have Windows XP installed on it. I have cable internet. My roommate uses the cable, so what do I need to purchase in order to set-up a wirless connection? A PCI card, different router? I really do not have clue, or a choice in the matter. I would appreciate any help/guidance in this matter, even a referral to a website. Thanks, Bryan

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic