I did a bunch of dumpster hopping in our various recycle centers around town, looking for keyboards for this Mario mosaic.
The keyboards were disgusting, skin and split coffee and general keyboard goo all had to be cleaned and re-cleaned in a soppy bath, then dried and sorted.
I had found some old Mario pixel art which I redrew to the right number of pixels needed for the mosaic in Photoshop. Then it was just a matter of paint by numbers, filling out from center to edge. I used space bar keys to add a sense of travel or 'speed lines' to the picture and worked in circles from the center out so as the keys varied from batch to batch it made a sort of vignette.