Opportunities for your age is a web application which shows opportunities (sports, computations etc) available around the world for your age
Create a special air conditioning system for helmets. This would greatly help the bikers in hot weather.
Give honey back to the bees. Lots of people have 1/2 eaten jars of honey. Put it outside a hive and give it back.
Social network that help find lost pets. You do check in where you lost your pet or where you saw a pet lost, with a picture of him.
http://www.laserpuissant.com/120-lumens-mini-lampe-torche-prix.html ?20 lumens mini lampe de torche
Public transport for free. Paid by sponsoring or taxes => extremly good for nature & would make taking the train/bus hip again
I would like a scanner in a school that sends the scanned image form a document or picture directly to the internet, with cost $ for sure.