Are you male or female? How tight are your jeans?
Depending on the fit and size you can go from seeing how much change someone is carrying to hiding a brick in your pocket!
Fortunately enought I wore jeans today, so:
As a guy wearing lucky brand bootcut 181 jeans that fit properly it is almost unnoticable. Someone looking for it would be able to spot it when I was walking but standing still it is slim enough to disapear.
Someone like my girlfriend or one of those cool hipster guys who favors a tighter fit might not be so lucky though!