I often participate on online petitioning in a range of subjects from protecting marine turtles to opposing Malaysia's development of oil palm production in the Amazon.
Petitioning can be effective!!
There are plenty of worthy petitions around, so if you are truly concerned and want to make a difference, I would urge all to participate. Be the change.

Help Stop the Trade in Bear Parts
secure3.convio.net/bfusa/site/Advocacy
Planned cellulose factory puts Tasmanian Devil at risk of extinction
www.regenwald.org/internati...aktion.php
Stop Canada's Cruel Seal Hunt: Boycott Canadian Seafood
secure.humanesociety.org/site/Advocacy
Ask Your Senators to Stop Big Coal from Dumping
Toxic Mining Waste into Our Streams
www.ilovemountains.org/write-...nators/
Taking the Wrong Path on Protecting Right Whales
action.earthjustice.org/campai...le_1009
Dutch government finances (ir)responsible soya
www.rainforest-rescue.org/prote...on.php

Thanks