Fresh oranges

A good orange's stems and surrounding area will be firm. A poor orange's "pole" will be mushy and will give easily.

Ooh lolli lolli lolli

In WWII, the Allied powers used "Lollipop" as a code because they knew the Japanese couldn't pronounce it.

Crepitation

If you've got a joint that "creaks" when you bend it, that's known as "crepitation"; the word is derived from a latin word the was used to describe the creaking of ships' hulls.

Protein in the woods

If you're lost in the woods, flip over a decaying log and eat the grubs (aka beetle larva). Eating a few will you give you enough protein to last you the week.

Cycling Machine

Cycling machines typically won't power up until you begin pedaling. The "quick start" button will only work after that.

C/CE

The difference between "C" and "CE" for Calculators is that "C" clears all entries, while "CE" only clears the most recent entry.