How can my friend build a portable windmill? Does anyone have websites, or explain to me so I can help her out? Thanks...she wants to power a lightbulb. :D

Lots of links here. http://www.otherpower.com/otherpower_links.html

I picked up two stepper motors on Friday at a local surplus electronics shop. They are each about 20 watts though I need to see what kind of RPM my windmill idea will drive them at. Much higher wattage ones are available but at a good deal more cost (I paid five bucks apiece for these). One of the easiest things to do is power a light bulb from a stepper motor as an AC generator, don't have to rectify the voltage or anything and as long as the bulb can withstand the peak wattage, no problem. I picked up an old BMX bicycle someone was throwing out last Wednesday. My plan is to use the two wheels mounted parallel to each other with the vertical axis between and then perhaps some wiring between the two rims to make a kind of cage. Though I think the specific idea for the vanes I plan to use hold promise as the most efficient, any design for a vertical axis type windmill could be incorporated into such.

Then again, you could strip a small stepper motor from an old floppy drive and somehow hang your vanes from it and that could be enough to power a small bulb. I made a wind vane with the idea I have in mind using a stock tinkertoy play set without having to modify any parts. I saw something like fifty of those stepper motors going for just a few bucks on eBay the other day.