TV and Film bags | Three Wise Stormtroopers tote bag
Stormtrooper tend not to carry bags. Apparently they're too hardcore for that, or they're just busy defending the empire or what not. Either way, they probably should carry some kind of storage device to hold small quantities of the force in. It could be useful.
Until we have the technology to harness the force, you'll just have to make do harnessing your shopping and possesion in this epic tote bag. Enjoy!