Sponsor essay and and/or public speaking contests. It could start in the Boston area. You can add prestige to it by having volunteers from prestigious universities act as judges and award presenters. MIT, Harvard or Tufts are examples. Teachers would submit the best essays on topics that would range from Children for Change regarding social issues, creative solutions to climate change or any relevant topic. This encourages children to think creatively and train to become leaders. Maybe famous singers or movie stars would get involved with the award ceremony or a documentary could be made of the process for PBS.
Another option is to get a sponsor to fund a prize and an organization like The King Center involved in presenting an award for The Best Ideas for Creating Equality in the World. I think sometimes children have passion and ideas but don't have a means of expressing them.