Dude. How about a hot guy for the bills? ONE. Just ONE. No chicks will be for this (I include me in this.)
Currency could still be made visually pleasing. I should be president. Our money would have good looking people of both genders, with two different notes for every value - this way everyone would be happy! PS - You can be like, VP or something. PPS - Only if you mail me some pop tarts. I can't buy them here.
Lets hope the currency does not go postal, cheep looking ready made for obsolescence - suggestive while engraved would be fine.