I've never been a fan of web on a cell phone. I had it for a month several years back. It was cool, but was just a toy, nothing more. The screen was so small you could not do any real surfing on it. You couldn't hook it up to a computer, so you could surf from there. Why pay $20/month to have Internet in a screen so small it would be useless?
My opinion is beginning to change. My main problem with web on the phone is that a) the screens are too small and b) you can't connect them to a computer. Android is changing the latter and there are now phones with bigger screens.
The screens are still small. I'm with Sprint and my Rumor 2 has a tiny screen, less than 2 inches on the diagonal. Well, Sprint/Nextel now has 4 phones with Android on them, the HTC Evo having the largest screen at 4.3 inches. This is still small, but when I checked out shabamdevelopment on it, I could just read the site. When I pinched to zoom in, I could read better.
I also played with the Samsung Moment. It's 3.2 inch display palled next to the Evo and I could not read the site until I zoomed in, but I could see using it for surfing. Samsung is releasing a new 4G phone they are calling the Epic very soon. This phone will have a 4inch display, with a pull out keyboard. These larger displays may well make these a valid replacement for a PDA.
My other complaint that you can't hook it into a computer is also voided now. It used to be that you had to get an extra devise to get a connection on your laptop through the cell carrier. There's an app for that. Sprint can't stop you from hooking your Android phone up to your laptop and getting Internet. So, now for the normal Internet fee, you can have Internet on your phone and laptop wherever you are! I think it is worth it.