Electric Lawn Dart! Solar/Wind AA Battery Charger for $5.

Take one of those cheapy rechargeable yard lights.

And an old PC's cooling fan.

Break away the plastic housing.

Break off all of the components, ie- resistors, chips, and the like.

Solder wires to all three coil posts.

Epoxy the fan to the cap of the light and run the wires out the side. Split the stake with a hacksaw and glue a tail piece in place. (I made mine from an old lamp base cover, but any flat piece of plastic would work, like a ice cream bucket lid or something.)

Find a full wave bridge rectifier (get one smaller than this). Or make one out of diodes. This will convert the alternating current of the fan into direct current which we can use to charge the batteries.

Test with wind source. I can get about 4 to 9 volts with just the fan.
The solar panel only gets about 2 to 4 volts.

Drill a hole sideways through the original cap (with the solar panel in it) just big enough to run the tube through. Add a diode to the negative side of the solar panel's leads. (This will keep the voltage from going back up into the solar panel and burning it out.) Wire the full wave bridge rectifier into the solar panel cap. Run a long wire out the side from the solar panel's diode and the DC negative of the rectifier to reach to the back of the tube. Run DC positive to the front of the tube, solder it to a spring just wide enough to fit in the tube. Place rechargeable AA Batteries in the tube.

Top view of solar panel cap on tube.

The tail is held on by a small cotter pin.

A small spring is soldered to the wire to make a good contact.

Drill a hole through the clear plastic housing and mount on top of a rod of some kind. Make sure it can rotate freely.
Now don't just leave it out in the sun on a windy day without adding some kind of limiting circuit. You might want to add a 5 volt regulator too. But if you check it every so often you will figure out how long it takes to get a full charge. DON'T OVERCHARGE YOUR BATTERIES!
Now it's up to you what to do with it.
Mount it to your bicycle helmet!
Mount it to the ski rack of your car and run some wires through the car window and into a Minty Boost to create a USB charging station!
Mount an old analog voltmeter to the top so you can tell when the batteries are full.
Make a crosspiece for the tail and mount two more solar panels on the top flats.