I have a blackberry pearl flip and I love it. It looks and feels like a normal phone, but has all of the convenience of a smart phone. I've had T-mobile for awhile and we have a great family plan that I can't get anywhere else. Yes, the iphone looks cool, but I'm an avid hater of all things made by Apple, so I'm resisting it as long as I can. Maybe when other carriers are offering the iPhone, I'll go to the darkside, but it will be at least a year before I can get another phone.
In answer to jeb's question, I know for T-mobile, they require a data plan in order to qualify for the phone rebate. Maybe if you can find a cheap phone that isn't part of a contract/rebate program, you might not have to get the data plan.