The Dollar ReDe$ign Project has provided some interesting and beautiful options that may make their way into
Why a vertical format? "When we researched how notes are used we realized people tend to handle and deal with money vertically rather than horizontally," they note on the Dollar ReDe$ign Project's website. "You tend to hold a wallet or purse vertically when searching for notes. The majority of people hand over notes vertically when making purchases. All machines accept notes vertically. Therefore a vertical note makes more sense."
....see more designs at the link below.