According to Ars Technica, the AT&T's iPhone bills are a complete waste of paper and resources. They just noticed now with the iPhone, but the fact is that it's the same with any of their smartphones: the bills can go up to 52 double-sided pages and beyond. So yes, it's a total waste. Apparently, AT&T itemizes everything in the most stupidly detailed way:
For instance, I know that on July 27 at 3:21 p.m. I had some data use that, under the To/From heading, AT&T has helpfully listed as "Data Transfer." The Type of file? "Data." My total charge? $0.00.
Personally, I think it's great that they give all the detail they possibly can, but here's a free tip for the guys running the Death Star: send the bill with the short summary and provide all those details on-line (they do completely paperless billing, but you have to turn it on online. By default you will get the snail mail 10-ton bills). And while you are at it, create a special billing page optimized for the iPhone screen. That way, people would be able to check their usage and spending anywhere.