It's not hard to spend more on international roaming charges abroad than you did on the ticket there, but cloak your cell's SIM card with a KnowRoaming sticker ($35) and you could be chatting and Snapchatting your heart out while only shelling out for local service. How? It recognizes when you've left your coverage area, and rather than switch to roaming, it seamlessly routes you through a local provider. They, in turn, get compensated for your talk and data usage via a prepaid account (which you manage via a dedicated app). And you won't be need to use alias digits, either, since calls to your regular number are automatically forwarded.