www.ibutton.com sells all sorts of jewellery, keychains, dogtags, etc with embedded ibuttons. If you got the rings used for unique ID's you could log into PM with your "ring" or "medallion".
I believe I remember stumbling across people who handle custom logos for ibutton-wear. If there is an interest, I will see if I can hunt up the sites again.

if that doesn't put your cereal box decoder ring to shame, I don't know what will:)