My Swiss Army knife has a screwdriver on it. It's nice to have, and I even used it recently.
It juts out perpendicular to the middle of the knife's body though, making a literal " |- " shape, so for many applications it's too awkward for the job.
I also have a more traditional screwdriver. As and when I come to build a new PC, I don't think I'll be using the one on the knife.