Wikipedia
Nanobama
Nanobama is the name of microminiature portraits of United States President Barack Obama.
To celebrate the election of Obama and to draw attention to the growing capabilities of nanotechnology, Professor John Hart of University of Michigan's Mechanical Engineering department created the world's smallest presidential portrait, measuring 500 μm across (about the size of a period in the average printed text).
The portrait is composed of some 150 million carbon nanotubes. Hart actually created the portraits before the election's outcome was known, and he let the secret out to the world in early November 2008.
There are several Nanobamas extant, but they all reside on a silicon wafer in the professor's office.