Yes, in post offices around the world they offer many services besides dealing with post. You can change currency, pay your bills, tax your car, collect your pension, buy phone cards, money orders - so many things.
Your vote on this answer has already been received
Yes, there are Post Offices in Great Britain (U.K.), Canada, USA. In fact, the Indian Postal System has the widest coverage and the world is impressed with the efficiency of Indian System. A Canadian team visited India to study our functioning so that they can adopt many practices that we follow in India.