In one foreign country that I know of (Mongolia), can pick from a list of available phone numbers when you sign up for service. They also hold them as commodities which can be bought or sold, as some of the older numbers had a numbering scheme which made them seem more prestigious. Each network has different numbering schemes, so you can tell what network someone is using by their number. Unfortunately, networks also charge more (or at least used to) for texts/calls between networks than within the network.