We finally received our R4 Revolutions for DS today! After playing the R4 for a few hours, we decided the default skin had to be replace with something more Mario friendly. :) Here are a few skins we slapped together. All of the skins below are available for download. UPDATE: The old skins were scrapped and updated with the following Super Mario Bros R4 Skins:
To replace the default R4DS skin, extracted the .ZIP and then copy the “_system_” folder to the root directory of the microSD card.

1UP R4DS Skin	8-Bit Mario R4DS Skin
Download 1UP R4DS Skin	Download 8-Bit Mario R4DS Skin
Wii Love Mario R4DS Skin :)	Toads R4DS Skin
Download Wii Love Mario R4DS Skin :)	Download Toads R4DS Skin
Background used for all skins:

Don't know what a R4DS is? Read this