Behr has a number of color picking tools to get your creative paint juices flowing. How to video of Behr's site.

Exterior, interior, and even tools for matching paint to fabrics, cabinets, and furniture.

Here's 7 more you might like:

Plan3D's Color Picker
Some people use the color picker inside Plan3D which shows you several types of complementary colors:

• Monochrome
• Double-contrast
• Soft-contrast
• Basic contrast
• Analogic-contrast