There's a rather unpleasant habit amongst Americans who own portable electronic devices: they insist on wearing them on their belts for all to see.
It doesn't seem to matter what the device in question actually is, nor how many of them are owned. I regularly see people with both BlackBerry and mobile phone proudly displayed side by side on the belt.
There's the obvious security issue with advertising the fact you own one of these devices; but there's also the fact that you look like a dork.
What's wrong with a pocket?