Ben Heine, the artist behind the famous Pencil vs. Camera project (previously on Neatorama), has more art tricks up his sleeves. This one above is his modern take on pointillism, which was made famous by Georges Seurat's A Sunday Afternoon on the Island of La Grande Jatte.
Ben called it "Digital Circlism" and wrote:
This portrait is only made with "flat circles" on a black background. Every circle has a single color, a single tone and a single size. I placed each circle one by one. It's a time consuming method. Please see some details, the work in progress and other portraits here below. If you wish, you can also view this making of my portrait of Elvis Presley (video) to understand how I'm exploiting this technique with circles...
Link | His full Digital Circlism gallery over at deviantART