I still own and use a Blackberry for its email and web capabilities, both of which outshine Apple's product. Because the iPhone doesn't have a search command, and apparently doesn't store messages locally, it makes a poor choice for a mobile email client.  

On the other hand, the iPhone is much prettier than a Blackberry and feels better in your hand. I'm not mocking Apple for that, style matters, esp in a personal device.

The other functions of the iPhone, the camera, YouTube, the photo browser, even the iPod functionality, are nice to have, but none of them work very well, and without a functioning web and email interface, they don't add much to the appeal of the iPhone.