I just printed a Heptagonal-Finger-Ring for my wife. I like 3d printed jewelry. And I also like to work with heptagons. I dont't get that chance very often, since they don't make patterns that easy - at least not in an euclidian space that doesn't cause your mind to explode

http://www.local-guru.net/blog/2011/10/8/3D-printed-Heptagonal-Finger-Ring