This year my kids main present is an xbox 360 to share. Now you just know that once they open that and its games they're going to want to be on it all day.
So, do I:
let them have an hour on it straight away but then make them come off? (will possibly cause tantrums)
Tell them they can't go on it until after tea (will NOT go down well!)
just let them go on for as long as they want..it's christmas! (great for them but bit boring for me!)