
This one is really interesting. Here you can find book covers by its colour. Simply enter a hex value in the search field and hit enter and you get: Lots of books with covers in your selected colour. Really good if you are looking for some new graphical inspiration 
Here you will find over 1500 different color palettes that were extrapolated from Sartorialist clothing pictures. Really great color resource which is updated daily.
This is a nice color scheme tool: You enter a word or phrase and it grabs 5 related images from Yahoo Images, and get the 6 most prominent colors from each.
Here you can create your own color scheme from your images. It is a re-scheming technology based on how the eye perceives color.
If you have to draw hair, then this site can be interesting for you. Here you find a nice hair color chart. (Hmmm… i didn´t know the color “LIGHT STRAWBERRY BLONDE FROSTED” yet
)
The Color Contrast Visualiser allows you to visualise good colour combinations on a Photoshop style colour picker. It’s primary use is finding acceptable colours from an existing inaccessible combination - while maintaining the aesthetic appeal of the original.
“Sick of having to open up Photoshop, or another graphics program just so you can get a Hex value? ColourMod for Konfabulator brings ease and simplicity to colour picking on Windows and the Mac.” Sounds good to me!
Well, now THIS is a really interesting sort of color analytic. If you like paintings you should check it out. And if you just like colors: Check it out too! 
At colorhunter.com you can create and find color palettes made from images.
Last Comments
Tom: really nice interview and a great person i´ve met in twitter. i just wonder when calvin is sleeping, seems he is a...
Jeny: Also, www.brandslogotypes.com have more than 130.000 brands logos in vector formats
Rizzi: Hello, loved these…definitely gonna use this
Gopal Raju: Thanks for including my icon set! Gopal ProductiveDreams.com
chad: Nice interview, Cal. Of particular interest to me was the schedule question, since I have been wondering how you manage...
Carlos Bracho: because, I want to have my own Cards with my own design, with the konowledege that I’ve learned at...
mayhemstudios: @Chad Engle - Thanks for backing me up and the kind words. :) @David Airey - I must have built up my tolerance...