If you're building a site and you're in need of some inspiration, check out the Colorcell project. The object of the site is simply to find the most beautiful and complimentary color combinations.
The creators of Colorcell have set up a funny competitive ranking system. Users can create their own 2 by 2 colored cells or vote on cells that have been posted by others. If a lot of people vote for a particular color combination, that cell gets to stay "alive." The rest of the cells go to rest in peace in the cemetary. The most popular cells get to live in something called the livingspace, which is refreshed every day. There's only room for 100 cells in the livingspace, and the more full it gets, the more cells die. So very strange.
Developers have largely ditched the traditional Web-safe color palette, a sea change that the Razorfish guys deftly documented some time ago on these pages. The move to more daring or more organic color combinations in site design is yielding some incredibly creative art like the Colorcell project.
So if you see a cell you like and you want to use those colors, grab the JPEG, pull it in to Photoshop and flex your color dropper tool skills! And don't forget to thank the person who created the cell in the first place.