My six-year-old came into the den the other day and fired up his pc. He had heard a website address he wanted to check out. It was pbskidsgo.org. He has played games on pbskids.org before, and this new area seemed geared toward his age group a little more.
After an hour or two of gaming over a few days, I noticed him watching a video called Bluefoot. It's about some young people trying to make a case for the existence of a bigfoot-like creature based on some pretty sketchy evidence. The story does a great job of explaining healthy skepticism, useful evidence, and simple belief. I was impressed.
To find it, visit http://pbskids.org/electriccompany/#/Videos, then click Episodes and Bluefoot.