New from T-Mobile: sane international roaming charges -- free SMS, free 2G data, $0.20/min phone calls, and in 100 countries. You can pay additional dollars for blocks of higher-bandwidth data, which falls back to 2G speed when the block is used up.

When I'm on a typical international business trip, I only really need the local phone network while I'm in transit. The destination hotel or university typically has perfectly functional WiFi, and I'll typically not bother with local service, for all the pain of dealing with getting a local SIM card, keeping it charged up, etc. This new T-Mobile thing seals the deal for me. The only missing feature is T-Mobile's WiFi calling, which is only supported on devices you get from them. There's no app or whatnot to enable it in general on devices you bring yourself.