Whether it is dark circles, age spots, freckles, etc., use Bare Minerals foundation. Their loose powder foundation (which has SPF 15 sunscreen) can be applied with a concealer brush for undereye camouflage, and for extra coverage, just dampen the brush. I am always skeptical about claims like this, but I was amazed at the coverage. It covered a bruise on the back of my hand!
The only thing is, I don't know how you would find the right shade unless they have a boutique near you. I was given a gift set for my birthday, by my daughter. The salon she works in just started selling it, and I was able to go there so she could match my skin color. I wear Medium Beige, 2.3. It is very transluscent.
I think the starter kit on the T.V. "infomercial" includes two shades of foundation, brushes, an instructional video tape, a bronzer type powder and a finishing translucent powder, and other stuff for around $60.
Good luck!
http://www.bareescentuals.com/