Clayton Gee is offering to assist campaigns in the upcoming spring elections with graphic design for computer and iPhone backgrounds (or wallpapers), bumper stickers, and yard signs. Several of his designs are available to be downloaded and used for free:
Other examples can be found here.
All Libertarian Party affiliates and candidates are authorized to use the items without gaining further permission.
Clayton has offered to assist campaigns for free and can be contacted at firstname.lastname@example.org or at http://www.facebook.com/ClaytonRayGee.