
I have a chapter in this excellent book, along with a variety of international artists and designers, including Jonathan Harris, Carla Diana, and Aaron Koblin. The book includes step-by-step tutorials by each author.

Plumage is the first of two Flickr tools designed to decontextualize colour in an image. Here, the colours from an image are analyzed and stored in an array. The colours are then sorted and re-rendered as feathers. Each image creates a new, unique feather. Clusters of feathers are built from Flickr keywords - so we are able to see what kinds of colour sets are being associated with various words and phrases.
Because the colours are separated physically and conceptually from the original image, we are able to discover relationships that we may not have been able to otherwise see.

Here are some things to try:
Plumage was built in Flash, using ActionScript 2.0. It uses Kevin Luck's excellent Flashr wrapper.