Here's a very cool tool for designers: The Color Fields Colr Pickr. It's a simple tool that gives you the ability to see Flickr photographs that match colors you select on a color picker.

Clicking on one of the swatches in the Colr Pickr returns a set of twelve photos matching your color choice. The photos, of course, are pulled from Flickr. Sliding the black levels selector on the right will result in a new set of twelve photos. Everything happens dynamically behind the scenes.
Colr Pickr creator Jim Bumgardner (shouldn't that be Bumgardnr?) claims that his mash-up is "a toy... simply to provide wonder and delight. Nothing more, nothing less." We beg to differ. Tools like this one which match Flickr photos to some sort of contextual design element are useful for web designers. During those moments when you're feeling blocked or uncreative, something like the Colr Pickr shows you the potential variants on a design. It can take you to new places and open up new possibilities. And, yeah, it's also a fun to play with.