I made this from a thrift store blazer, rather than buying fabric new. It cost about $9 (in expensive San Francisco) and I'll get another 2 hats from it, easily. If you have fallen in love with yardage, you'll need about a third of a yard -- but take the pattern to the store and lay it out there to be sure.
For the brim, I use a piece of flexible clear plastic of the kind blister packages are made from. Many packages have large flat areas from which the plastic can be reclaimed, although a lot are just too closely molded to the product. I have a stash of flat plastic for brims. Yay reuse!
The only other material needed is a yard or so of quilt binding or wide bias tape for the inner hat band. Tools required are sewing machine (although you could do this by hand as well), pins, and scissors.
Update: pix of one made from paper! http://www.flickr.com/photos/29317731@N08/sets/72157617448800455/
Step 1: Pattern
I have not worked out a good way to get a paper pattern into a computer. If anyone has a good idea I'd love to hear it. Anyway I traced these in Photoshop... I didn't take the estimated 4 hours I thought it would take to add the seam allowance, so each of these shows only the stitching line. When you print them out, you'll want to cut a quarter inch out from the line; it may be easiest to draw the cutting line on first.
Also: the sizing is probably not correct. I marked a red line with a number of inches on each file, so you may need to make some xerox adjustments to get that marking to the right length.
Thanks for your patience everyone! Please post pictures of yours!