Before you click the map, it's pointless (ha ha - get it?)

I can only think of limited uses for this, but who am I to pre-judge the usefulness of something? Google Planimeter lets you trace points around a Google map, then the area represented by the trace is displayed at the bottom of the screen. So in this example, I traced around Parc Gatineau near Hull, Quebec. It's huge! About 370km squared. Or 143 square miles.