Estimate Distances

Cool distance estimation trick from LifeHacker (and proof to the kids that math class pays off some times):

Estimate Distances with Your Arm and This Rule of Thumb [Macgyver Tips]

Math is Fun

Quick anatomy lesson: the distance between your eyes is one-tenth the length of your arm. This is important, because it helps you estimate the distance between yourself and any object of reasonably known size to a rather accurate degree.

Imported from an old blog. Some links might be dead. Let me know if you find dead links. (Dead links replaced with similar)