Leave Your Card!
I assume all working pros do carry a few business cards with them when performing, ready to be handed out when anyone makes an enquiry. Also, when performing at a Community Centre it is a good idea to leave a couple of your cards pinned on the general notice board.
To this end it is useful to carry a few drawing pins with you. There are very rarely spare pins on the board and it isn't a good idea to pinch from other displayed material.
The easy way to carry a few pins without a constant rattling bulge in your jacket is the gist of this tip. Simply get a small rubber eraser and push a few pins into this. These can be carried harmlessly and without inconvenience in your pocket at all times.