I have a work-issued BB that only has data, no phone, so I use my personal cell phone for my business calls (reimbursed work related expense, of course!). So yes, I
used to carry a BB and a cell phone.
This past December I replaced my personal cell phone with my own BB, so now I have to carry 2 BBs...and it makes me feel so superior to most other people
I know several of my co-workers carry both their work BB and personal cell, but it's usually to keep the work and personal emails and phone calls separate from one another.