A Geek News article about the wireless Internet suggests the technology is getting more and more popular -- but handheld wireless devices remain pretty much unusable, because most sites don't cater designs to them. The article's author opines:
I have been surfing the Internet on handhelds for three years now. While things have improved from the beginning, it's still, basically, a nightmare. I feel for Web developers, having to decide whether to fork their site once more for mobiles or attempt to make one version of the page that satisfies all screen sizes. Whatever most of them are choosing to do is not working.
In my mind, the answer is simple: Make sure your Web documents have a logical structure, and move all formatting into a stylesheet. Then designate a stylesheet for each browser type you'd like to support -- from standard Web browsers to handhelds to vocal browsers. Don't enlist programmers to output entirely different HTML pages for each medium; instead, do it the easy way.
This extends to "printer-friendly versions," too. Why make your users load another page just to get a printer-friendly version when you can use printer-friendly stylesheets instead? (A List Apart has a great article on this topic.)