Green Idea Of the Day II - Switch off the engines

Switch off the engines of your car/motor cycle when you are waiting! How many of us keep our cars/motorcycles running during those long signals? Or how about when we drop some one(kids at school, girlfriend at the mall etc) and spend a minute talking before we leave. Does the engine need to be on during the entire conversation? NO. Very easy to do isn't it? How much fuel would we save if we switched our engines off at every signal? Not much individually, but if many of us do it.... Think about it!