I have both a curve and a iphone. I am with t-mobile and have the iphone jailbroken with ziphone software so I can use any sim card from any carrier I want. I use to swap my sim back and forth between the two mainly because I love the iphone interface but hate the fact that it won't send or receive mms. I finally decided to keep my sim in the curve and put a pre paid sim in the iphone. I now use the ipone mainly as an ipod that happens to be able to make phone calls via the prepaid card. Plus I am now saving a few bucks since I use to have to carry the bis internet and the total internet from t-mobile to give them both internet access. Oh and by the way, removing the sim from the iphone is impossible if you don't happen to have a thin paperclip or pin handy to stick in the hole to pop out the sim tray. Swapping back and forth proved to be a pain in the long run to me.

~via BB (wap.pinstack.com)~