Personal Cup Holder

I walk to work, I often stop on the way and buy a coffee. Alone, this action would be fine. I have two hands, one for the coffee and one kept in reserve for itches and doors. However, I often like to buy a breakfast sandwich. This puts me in a very awkward position. I can hold both the coffee and the sandwich easily, but then I can't really unwrap the sandwich. So I have to stop and put the coffee down, eat about half the sandwich, so that it's manageable with one hand. Then I can carry on, sandwich in one hand, coffee in the other and a dangerously low hand-reserve. Imagine you had a cup holder about your person. Cars have long had a variety of folding arrangements that would prove a useful cup-holder resource. The belt seems initially logical, but moving legs might interfere here, so I think some form of cross-chest strap or possibly build it into a sturdy jacket, some form of gimbal arrangement may be appropriate for those fussy about relative beverage- gravity orientation. This would free up both hands for eating the sandwich, while holding it may be effectively achieved with one hand on a temporary basis. For example while attending to an itch, opening a door or investigating a newly-acquired sauce stain. Every now and then, the coffee could be accessed for the usual reasons. Such a device would be a boon to sandwich eaters, standing-around-in-very-cold-weather enthusiasts and the one-handed alike.