The Solarflower is an open source solar energy collector which can be made very easily from common recycled and salvaged materials, using basic tools and skills.
It tracks the sun automatically through a simple non-electrical mechanism, can be made almost anywhere, is portable, has no running costs or emissions, and can produce up to kilowatts of power per device.
Applications include electrical generation, water purification, cooking, bio-char and charcoal, heating, gasification, and whatever else heat can be used for.
Step by step animated tutorials are available at http://solarflower.org, as well as the discussion forum, blog, media, and other resources.
The project has no immediate needs in terms of financing or participation.
Ultimately it will come down to people to make and use the device as they see fit.
Finish and publish construction tutorials, currently about 80% complete.
Spam the internet and see what happens.
(Being more detailed and specific would I guess be helpful here, but once the project goes live it will be completely out of my hands how things turn out.)