Thanks to this post from feed growth blog by Atlanta's Digital Scientists, I've learned about ColorSuckr. If you can find the URL of a picture, ColorSuckr will extract the colors and help you do a color scheme. It's a free web application.
I've used the stand-alone program "ColorSchemer" for years. It has been very valuable. The ColorSchmer website has boatloads of great palates.
Do you know about ColourLovers. It's more than I can handle.