In your hand, strangely this is a very common way. - Problem, people put down on table in restaurant and leave or it is stolen.
Inside a Day bag - Problem it takes too long to open bag and retrieve to answer.
In Cargo Pockets on the side of pants. - This is maybe the best providing you do not have quick open Velcro, and there is a way to slow down the pickpockets.
Breast Pocket in a Sport Jacket
Clip on holder for belt. - Tells people you have something to steal. - The magnetic clips can cause problems for memory storage devices - Belts cause problems at Airport security checks.
In front pocket or rear pocket of pants. - The buttons will dial numbers