A key goal for bottom-up nanofabrication methods such as self-assembly has been to generate structures whose complexity matches that achieved by top-down methods. I describe a method for folding long single strands of DNA into arbitrary two dimensional target shapes. Self-assembled in a one-pot reaction from the 7 kilobase genome of phage M13mp18 and more than 200 synthetic oligodeoxynucleotides, the shapes are roughly 100 nm in diameter and nearly 5 megadaltons in mass.  Experimental shapes approximate target shapes, such as a 5-pointed star, with a resolution of 6 nm and may be decorated by patterns at the same 6 nm resolution to form words or images. These structures may be thought of as a versatile "nanobreadboard", a simple platform for creating arbitrary nanostructures such as nanocircuits.