I'm using a blackberry on U.S. Cellular. They have a new program called the Belief project, so I thought I'd call and see if I could get my $175 bill lowered (ugh...is it really that much...oh yeah...I have a pre-teen with a phone). After several minutes of talking and explaining what all she could "do for me," she said you're new bill would be $185. Apparently she didn't understand the concept of "lower my bill."
While I highly recommend U.S. Cellular, at $25/smartphone, the data plan adds up quickly (my wife just had to have a blackberry, too).