Let's see, on my personal line I got my iPhone 3G when it launched and got the iPhone 4 when launched. Before that I had a nokia n75, samsung blackjack the year before that, samsung blade a900 before that, motorola flip phone, samsung flip phone, moto flip phone (had a plug in camera and COLOR screen! I was soo cool), a nokia, a nokia, a nokia, and another nokia. So from 2000-2008 I went through 10 cell phones, and since then only 2 iPhones, I actually made it to the end of my contract with upgrading this past year and will probably again with the ip4.
Now, my business line which has no iPhone, that's a different story. Rigt now it's a palm pre plus, before that it was a blackberry tourch, Nokia 6655, moto razr2, moto krazr, moto razr. That's 5 phones from 2006-2010.