Tim and I made one digital art piece per day, for 365 days. When we started the project, the only constraints were that each sketch had to use Processing, and had to be an image or video as the final output. It got us to see what was possible with Processing, as well as our own abilities in programming these pieces.
For most of the sketches, we didn't spend much more than a few hours programming them. We used a bunch of libraries along the way for some really cool results, including Joshua Davis' HYPE framework, onformative's Leap Motion P5, and Hemesh.