I'm terrible with color. Terrible. So I intend to try to improve a little by coloring the cover images for the next season of Q-Burger. And one of the tools I'm going to use is Adobe's free web-based Kuler (they pronounce it "cooler").
Designers can browse thousands of color themes created by the Kuler community; including the ability to search for color themes by tags, themes, hex color, and more. So searching for spring will likely bring up a list of bright and cheery color combos appropriate for that flower landscaping brochure you're working on.
But it doesn't stop there. Users can also create new themes based on colors in an existing image you upload from your desktop. Once you've found a color scheme you like, you can rate it, add it to your favorites, export it as an Adobe Swatch Exchange file for use in any Adobe Creative Suite app, or add it directly to your CS4 app Swatches panel. You do so with a simple drop-down menu in the Kuler panel next to the swatch name.
I've already used it a bit on some web projects, but not extensively. I think it might be a pretty useful crutch for we color-confused folk.