Some utter genius of a girl, Camille, came up with these recently:
here. Christian Louboutin and YSL can duke it out all they like over their red soles, but these are 10x better. Or hey, Christian L, how about you do a red glitter sole for some holiday shoes?!
Long story short, the process involves glue, very fine glitter and a sealant. And don't bother putting it under the toe as it'll grind of in 10 seconds anyway and no one can/will see it. Do, however, coat the inside of the heel.