Ready for some rocket science? Hmm, well, you might have to look elsewhere then because this is way easy.
I use oat flour in several of my recipes and thought that it deserved its own little page. Homemade oat flour doesn't come out quite as fine as store bought, but it certainly comes close. It takes 3-5 minutes and it costs only about $.90/lb. I didn't find anything even close to that cheap online, even without shipping costs.
How to Make Oat Flour
1. Dump oats in a blender. They can be old-fashioned or quick (or probably whole and unrolled if you've got a decent blender, though I've never tried the unrolled variety). If you blend 3 C quick oats, you'll wind up with about 2 1/2 C flour.
2. Blend until smooth and flour-y. You may have to scrape down the sides here and there. And you may want to stop the blender once or twice and dig around in the bottom with your spatula to be sure there aren't any oaty pockets down there that you're blender is missing.
3. Use. If you have a lot, you can put the rest in a freezer bag and freeze it. Note: It's fine stored at room temperature for about 3 months. For longer storage, freeze it. Also, if you're looking for a nifty site about the storage of different flours, have a look here.