I carry a Nike Messenger Bag everyday, it was a "Giveaway" from TAGHeuer, it sat in storage forever, then this past year I started using it to carry Mail in (ie:Razor boxes) then I realized that some of the people I work with are a bit less than honest so I started keeping personal stuff in it instead of my desk drawers...
It is also waterproof in and out so I bring lunch etc: in it too..
I keep things like Nail clippers, Thumb drives, Ear buds, Ipod cords, Dental Floss, basically everything I don't want people walking off with or using, in it

The wifey refers to it as the "Male Bag"