Earth Hour was a big hit at our house. The little ones were already fast asleep which allowed candles to be scattered about the carpet. E&E and I played clue by "fire" light.
They has so much fun that they asked if we could have earth hour every night.
It was quiet and slow and peaceful and...fun.
There was such a limit to what we could do and the need to share candle light kept us all close.
I am glad for the global inspiration. We will do it again soon.