Handpainted wallpaper

Like I've mentioned before, I love the idea of hand painted wallpaper. I am too scared to even research how much the stuff costs, though, and am (perhaps insanely) considering undertaking the project myself (for a small space-- I'm not a masochist). I was checking out Decor8 the other day and ran across this swell design for wall decals and decided to try my hand at making something similar.