One product that is often on hand and works for most label and tape
adhesives is lighter fluid. It is probably made of naphta (which was in
the list of suggested products that Doug Miller posted).
Also, most oils, such as baby's oil, motor oil, etc. will soften the
adhesive and keep it from sticking back to the object. You just rub the
glue out with a little oil. If you use baby's oil, cleaning up the oil
afterwards is easy with warm water and dish detergent.