I've had a blackberry, a G1, checked out the droid, and I now have an iphone.
The blackberry is great for sending texts and e-mails, but browsing the web sucks.
The android interface needs to mature a bit as it's still pretty clunky compared to the iphone.
The iphone is great for browsing the web, but the blackberry is the better choice for sending texts and e-mails.
I'm sticking with the iphone for a while until the android UI is a little more polished.
If you decide to get an iphone, check out these apps:
Bump - great for quickly trading contact info
5 MPX Camera - makes your iphone take pictures that are as good as those taken by a 5 megapixel camera...takes a while to save between each shot though.
-SDT