This particular project (making solar fans and experimenting with solar cells) might be of special interest to those who work with youth. I’ve found that young and old enjoy experimenting with the fans and solar modules, as well as learning about renewable energy and the environment. It provides a gentle introduction to photovoltaics, and makes a great hands-on activity for a gathering of many sorts!
The instructions (and parts list) are in the video, but in a nutshell, here are parts I used:
I went with a 2 volt, 600ma solar module, so that it would feasible to power the fan from an indoor lamp, as well as directly from the sun.