I've been setting up my new Blackberry Curve 8320 and it provides a striking contrast to the iPhone, both positive and negative. The 8320 is a lot more complicated and harder to setup, but then it's much more functional. It supports third-party applications but so far I've only felt a need for two, Bee Jive - a multi-client IM program, and Google maps, both recommended by Dan Hendricks.
It comes with a nice range of programs including a password vault, very capable voice dialing, it's own mapping program designed for use with a third-party GPS unit, and a Breakout game. There's an ok browser that's not as good as Safari and a media player also not as good as the iPod but with limited storage you're not going to be using this as a music player. Blackberry is a phone first, email and messaging device second, and media player/browser a distant third.
It doesn't have a touch interface but the pearl trackball works nearly as well with Google Maps, and the physical keyboard is lightyears easier to use, and more accurate, than the on-screen keyboard. I do greatly miss the classic Blackberry thumbwheel. The pearl just feels cheesy and seems less practical even though it does give you a broader range of motion. The two-megapixel camera is not much better than the iPhone's although it does seem to offer better white balance and optics. It's too slow to use for anything but the occasional snapshot.
Of most interest in the 8230 is Wi-Fi support. The phone comes out of the box with integrated VOiP (!) and will use the Wi-Fi for calls in lieu of the T-Mobile network when it's available. This is exactly the kind of thing AT&T must most have dreaded on the iPhone, but T-Mobile encourages it. Talk about different world views.
The 8320 out-of-the-box experience is nothing near as slick as the iPhone's. If I hadn't had a lot of experience with Blackberries I'd be lost. It's pretty obviously intended for an IT department to set up. As it is I'm having trouble configuring email. T-Mobile doesn't seem to know I have a Blackberry and hasn't sent the needed software down. Beside the usual Blackberry corporate support, the phone also works with Yahoo Mail, Gmail, and other POP systems. It appears to poll these systems periodically for mail.
Bottom line: The 8320 is a complicated device and there's a steep learning curve. It's not as beautiful as the iPhone, or as functional as a browser and media player, but it's many times more useful for email and messaging. I've always loved Blackberries, and the 8320 is the most elegant Blackberry yet.