Well, Whadya Know

Why do we call that suite of playing cards with the cloverleaf symbol, "clubs?"

The English adopted the symbol for this suite from French playing cards. On French cards, the symbol was clearly a cloverleaf, the French word for which was "trefles," meaning "cloverleaf." So, what did the English call it? "Clubs," naturally. In the great tradition of English eccentricity, the people of that green and pleasant land took the translation of the Spanish word for the same suite, "basto," which in English is "clubs," and applied it to the cards that clearly depicted a cloverleaf.
[source: Why Things Are & Why They Aren't by Joel Achenbach]

Why is there "snow" on the TV screen when a station goes off the air?

Ordinarily a circuit in your TV's amplifier either boosts or diminishes broadcast signals, depending on the strength of the signal. But if there's no signal - as when a station goes off the air -- this amplifier circuit, called an automatic gain control, boosts to the maximum whatever it picks up. In the absence of a broadcast signal, it's picking up and amplifying random static emissions that could come from your pc, vacuum cleaner or other circuits in the TV itself. Without any signal at all you would see a white screen. The electronic static shows up as moving dark dots which, blended with the white, appear to be snow.
[source: How Do Astronauts Scratch An Itch? by David Feldman]

Why do people who lose their temper "fly off the handle?"

Tool handles were made from wood, which shrinks over long periods. The shrinking wood loosened the head of the instrument. The first good swing could send that head flying, with serious consequences for anyone standing nearby. Similarly, someone metaphorically flying off the handle is momentarily irrational and perhaps even dangerous to those near them. It is also said that such people "lose their head," which is the same thing as saying that they fly off the handle. Of course, when that used to happen literally, anyone standing close enough could lose his head, too.
[source: Why You Say It by Webb Garrison]