It's on Etsy now, so go take a look - HERE
All you need is 75g or so of DK weight yarn and some 4mm dpns or circulars. Because of the continuous scallops and eyelets, you will not be able to convert it to a flat pattern and seam it, I think. It won't make for an attractive end product as the seam probably won't work. It measures aout 19 inches and stretches easily to accomodate my head which measures a little over 22 inches. I guess that makes it a good chemo hat pattern as bald heads are slightly smaller. To make it larger you can try using slightly thicker yarn on 4mm needles. Let me know how you go!
I have also put up some hand-dyed yarn and stitch markers. I will be adding more hand-dyed yarn to the store soon, so keep looking.