Some of the OCC members have started creating WinAmp themes, longon screens, and even a desktop theme. Pretty damn cool if you ask me. 
Check it all out:
OCC Logon Screen
OCC WinAmp Skin
OCC Windows Theme
If you’ve got the skills to create application themes, skins, or wallpaper and would like to make some for OCC, the information you need can be found here.