Hey, if Randall keeps writing them, I'm gonna keep posting links to them...today's XKCD What If is "If every person on Earth aimed a laser pointer at the Moon at the same time, would it change color?"
Unfortunately, the laser energy flow would turn the atmosphere to plasma, instantly igniting the Earth's surface and killing us all.
Today's XKCD must have taken Randall several years to draw...if you click and drag, it goes on forever. Or not quite forever, but Dan Catt did some figuring and:
Ok, so the XKCD map printed at 300dpi is around 46 foot / 14 meters wide, half that at magazine 600dpi quality.
Here's a better Google Maps-like way to explore the entire world.
With the assistance of a nuclear reactor operator, Randall Munroe came up with this handy radiation dose infographic. Doses recorded near the Fukushima plant compare to those from a single mammogram or dental x-ray. A note on how to use this chart:
If you're basing radiation safety procedures on an internet PNG image and things go wrong, you have no one to blame but yourself.
A wonderful character interaction map of the Lord of the Rings trilogy drawn by Randall Munroe. Here's just a little part of it: