In 2000 when the original iMac came out, people were amazed to see a wireless internet connection. Fast forward nine years (!!) and wireless technology is everywhere in our society.
It's easy to forget where it all started - with the Apple Airport card. Plug this in to your mac and get 802.11b wireless (11 Mbps) which will enaqble it to join your existing wireless network. You may scoff at the speeds, but most people don't have an 11Mbps internet connection, so it is more than adequate for browsing the web.
Original Airport cards like this are increasingly rare. They aren't made anymore and collectors are snapping them up. If you have an old G3 or G4 iMac with OSX 10.3.9 or newer, don't miss your chance to grab one of these!