You can buy baseball-style caps that come with a curtain of sun-blocking fabric, but because the curtain isn't held away from the head and neck by a broad brim that extends all the way around, the curtain tends to cling to the neck, and in hot weather, it can be quite uncomfortable. It's also hard to rotate the cap and curtain comfortably to adjust to different sun angles.
Pictured here is a broad-brimmed hat with a homemade curtain of SPF-30 fabric that attaches with three snaps. It greatly increases protection for your head and neck, and you'll hardly notice the curtain--unless it's quite windy out. On the following pages are instructions for making this ultimate sun hat.