building a generator can be a fun and fairly easy project. getting a large DC motor however can in some cases be difficult. here is a writeup on how to make a generator from an old washing device drive. It looks like you might need to find a particular device called the “Smart Drive” to follow their directions exactly though. If you happen to find one, or know of a unit with a similar motor, you can follow these directions to end up with a fairly respectable wind powered generator.
[thanks TripleB]