Plain old Nokia phone - the model they give you for free when I sign up.
I had a Blackberry provided by a company I contracted at for a year. It was really a pain to carry it around along with a cellphone. Two funny stories came out of it's use there. One was when a particularly boring product manager was going to give a presentation
on our work. We setup a scheduler to bombard his Blackberry with mail about every 30 seconds. He ended up turning off his unit after about 5 alerts when he realized he was the butt of a joke. The other was our manager who had a convertable Mustang and drove
fast and wild. She was pulled over by the police one day for reckless driving. She was talking on her cellphone and thumbing an entry into the Blackberry while trying to stay on the road and in her lane, apparently not too successfully.