I carry the Nexus 4, a little old Nokia feature phone as backup, and a micro-sim cutter. If I am staying somewhere for a decent amount of time, I'll use the smartphone and get a data plan. However, if I am only going somewhere for a short time, like my recent 3 day jaunt to Singapore, I will usually just get a sim for the Nokia, so I can text and talk with friends in the area/country.