The image was composed using a program called Mozodojo which is freeware and runs on Mac OS X.
For the source image, I simply took a photo of myself in the mirror. For the tile images to form the mosaics from I did a search in Aperture (Mac software) for all images taken with my Canon 20D challenge pictures with a 2 star rating and exported these to a folder as fairly small Jpegs (400 pixels in longest edge). This gave me about 1000 images.
Mozodojo was unable to access these images for some reason so I imported them into iPhoto and it was able to use them from there.
I played around with the size of the tiles and the intensity of blending with the source image. I wanted some of the challenge photos to be recognisable (just). However, because of the size limitations of the challenge images, I had to allow more of source image to blend in because theres wasn't enough resolution with tiles alone. I'm quite please with the result but wish I'd taken time to make a better portait as the source image. - Najinsky