Is there a way to handle external interruptions on iPhone / Android ?

Is there a way to do something quickly when the phone rings (or whatever), perhaps some callbacks that can be implemented? (I know the game is paused gracefully as is, I was just wondering whether it is possible to do something extra - save information, use the game's own pausing, etc.).

Turns out OnApplicationPause works. See here: Does OnApplicationPause actually work? - Questions & Answers - Unity Discussions