Basically, Multicolr, scrapes creative commons photos from Flickr's most interesting bucket based on visual similarity according to colour.
Multicolr offers you a pallette of 100 colours to choose from and as you select a colour it sucks in photos of the same colour. Even cooler, if you select two colours it scrapes accoridng to both colours (like the above panel – purple and yellow).
I haven't exactly figured out speciifc uses for Multicolr yet, apart from hours of endless fun and finding amazing images for presentation. If anyone has some better ideas please leave a comment.