I have a Macintosh iBook G4 that comes with a built-in Airport card. It works the same as the regular wireless cards (only it was included, and is somewhere inside the laptop, not an add-on) and I can piggyback on most connections, from up to 200 metres away. I'm also able to hook up a router to dialup and have it work, which is handy when I'm at my cottage or somewhere where high-speed is unavailable.
The thing I love about Macs (and Mac-compatible browsers) is that viruses, popups, etc. aren't normally re-written for Mac compatibility, so I surf the 'net relatively peacefully. The downside, of course, is that it's not as easy to find Mac-compatible software, but not an issue if you use in-demand products like MS Office, etc. It's when you get into up-and-coming products that it gets tricky. But if you upgrade the RAM to a gig, you can use Virtual PC for windows applications. (It's still pretty slow, tho.)
You won't find too many Mac users who say they wish they still used a PC.