For now, I am carrying both - yes, two numbers.

Each has it's advantages.

The N900 certainly has the ability to have the same types of applications as the iPhone, but it will take a monumental effort by developers and Nokia to match the best of what iPhone has to offer.

What I use on the N900 every day: phone calls, messaging/email (Gmail/Nokia Messaging), superior browser, Google Reader, gPod; free Wi-Fi at Starbucks requires jumping thru a few login screens, Flash

What I use on the iPhone: location/travel/restaurant services. Free Wi-Fi at Starbucks is automatec

My cheats: several websites are optimized for the iPhone. I've extracted those iPhone specific URLs and loaded them as shortcuts on my N900. Sometimes, these websites are quicker/easier to view on the N900, rather than the full-fledged websites the N900 browser defaults to

What I don't like about the iPhone: required to use iTunes if I want to do any sync'ing. I can't just copy files over to the iPhone when in a rush. Also can't just download some files.

Note well: since I am on ATT, I am limited to Edge on the N900. However, I find that 3G isn't always an advantage - for most things Edge does quite well in my area, and 3G isn't always faster. Sometimes 3G is quite slow, or won't even load webpages, while Edge will. Go figure.

My only dissatisfaction: two pockets needed to carry both phones.