A free windmill.

William Kamkwamba desperately needed water to grow food for his family in Malawi. He could not pump or carry it by hand so he built this windmill for free. He had an old school text that showed a windmill and a nearby junk yard where he found pieces of metal he could use. It was difficult for him to build because he didn't even have a drill to make holes but he got it finished and it worked.
Because this was such an unusual project he was selected to go back to school. He had dropped out of school when he was 15 because he parents could not afford the fees. He has since started a club he calls the 'Doers' and he hopes they will be able to do something useful in the future.