I imagine this is one of those things most people know about except me. I just learned about Adobe's Kuler web site and lab today. Kuler (pronounced "cooler") is basically a color lover's dream and a useful tool for designers, crafters, scrapbookers, etc. You can search for all sorts of color palettes based on all sorts of critria, and I just love the fun names on some of them! You can easily download the color palette directly from the Kuler website or open the swatches directly in Illustrator (Window>Extensions>Kuler*). I could spend hours here.
Above are a few color palettes that caught my eye.
From top to bottom: agave, retweet, tablo, my aspen watermelon, chocomint on steel and vintage blue.
*This is in CS 4. I will look it up for CS 3 and get back to you all. It's under Window, but I can't remember where you go after that.