It would have to be something that could be turned on and off depending on the user's needs. A background save every 5 - 10 minutes could spare one from much anguish when someone drives a pickup truck into the utility pole with your transformer on it and you suddenly discover the batteries in the UPS are dead.

It would also have to work in the background. Saving larger files takes a long time, and I don't want an enforced break in my work flow every 10 minutes!