Robert X. Cringely writes a technology blog for PBS, which I've read for a long time. In his August 29th posting, What Did You Say?, he discusses his unpleasant experiences as a new iPhone owner/user.
I have no iPhone experience, so I can't judge his opinions. However, Cringely's blog is always thoughtful and, to me, he is a very credible source. Plus, he has an excellent perspective owning two iPhones, a Samsung AT&T phone and having just switched from two other cellphone companies to AT&T.
In a nutshell, he says that the iPhone makes a miserable telephone.
The posting is long but only the first five paragraphs address the iPhone. For more about the iPhone, see CNET coverage.