This is a derivative of scooter46290's 'propeller for quadmini', intended for a miniature quadcopter. However, I've adapted some of the dimensions and hole sizes, and added a set-screw whole to accomodate both my preferred (and widely available) motors at http://www.pololu.com/catalog/category/60", and a powered glider design I'm working on.
Print with support, 10% or more infill. The final product is very fragile, so be careful taking off support. (I made mine with MiracleGrue/Replicator 2.)
After that, you can either:
-Attach to a 3mm dowel and use as a whirligig (This can fly about a meter in the air)
-Attach to a 3mm motor shaft and use it for flying devices or fans.
An awl or similar device might be needed to make it fit.