I was really impressed when I saw this video of an Australian classroom and how they are helping to create a better world. 
The thing about these actions are that they may be small, but the effect is huge, and can last for a long time...

I think that when we do things to improve the environment and the surroundings we help create peace as well.  For eg.  in one example the children are recycling the old mobile phones which if they were thrown in the garbage would create toxic waste in the soil.  With these toxins in our soil, it would affect our health...so they are helping to create better health for people.  With healthy bodies we can meditate easily, we can work easily, study easily etc etc...




Enjoy it, and hope you get good ideas!