I've created my very first skin, and it's for zLauncher, a 3rd party application launcher for the Palm OS. There are lots and lots of themes out there for zLauncher, but I've never taken a liking to any of them, including the default one that comes with it. They all look too gaudy and cluttered, or try to imitate the GUIs of desktop OSes which do not translate well to the small screen of the Palm.
Keeping in line with my clean and minimal design style, I've created FlatGrey (yeah, very imaginative name, eh?) It's mostly areas of flat colour, in grey :) accented with soft rounded corners and orange highlights. Take a look even if you don't have a Palm and tell me what you think. Currently available only for high-res OS5 Palms.