Earth Hour is more than a token - it is a symbol; the fact that so many countries participate shows that people want to do something. I had a Ploughman's Lunch type picnic by candlelight - it was so peaceful, that although I turned on the TV to watch a movie at the end of the hour, I did not turn on the lights.
On a similar topic, I read an interesting quote from the Australian Green's Leader, Bob Brown, today on mortality:
"I have never met a person in whom I did not see myself reflected. Some grew old and died and I am now part of their on-going presence on Earth. Others have a youthful vitality which I have lost and will soon give up altogether. These youngsters will in turn keep my candle, and yours, alight in the cosmos."