I don't know if they're all true but they certainly seem to be right.
Some of these I've heard before, but they are still entertaining...

The Sentence, "The quick brown fox jumps over the lazy dog," uses every
letter in the alphabet. (Developed by Western Union to test telex/TWX
communications.

In every episode of Seinfeld there is a Superman somewhere.

The average life span of a major league baseball is 7 pitches.

A duck's quack doesn't echo, and no one knows why.

The only 15 letter word that can be spelled without repeating a letter
is uncopyrightable.

Did you know that there are coffee flavored PEZ?

The reason firehouses have circular stairways is from the days of yore
when the engines were pulled by horses. The horses were stabled on the
ground floor and figured out how to walk up straight staircases.

The airplane Buddy Holly died in was the "American Pie." (Thus, the
name of the Don McLean song.)

Each king in a deck of playing cards represents a great king from
history: Spades ~ King David; Hearts ~ Charlemagne; Diamonds ~ Julius
Caesar; Clubs ~ Alexander the Great.

111,111,111 x 111,111,111 = 12,345,678,987,654,321

Clans of long ago that wanted to get rid of their unwanted people
without killing them used to burn their houses down ~ hence the
expression "to get fired."

Only two people signed the Declaration of Independence on July 4th, John
Hancock and Charles Thomson. Most of the rest signed on August 2, but
the last signature wasn't added until 5 years later.

The term "the whole 9 yards" came from WWII fighter pilots in the
Pacific. When arming their airplanes on the ground, the .50 caliber
machine gun ammo belts measured exactly 27 feet, before being loaded
into the fuselage. If the pilots fired all their ammo at a target, it
got "the whole 9 yards."