These kinds of things are always neat to read. Snopes recently featured an example of this (Billions and Billions | Snopes.com), but I’m interested in factual perspectives on otherwise difficult to comprehend subjects.
AMUSE ME 
From my college chemistry teacher:
If he water molecules in a regular glass of water (8 oz) were the size of golf balls, the glass would be he size of the earth…
If a sperm were the size of a sperm whale, the ovum would be the size of Japan. And the sperm would swim at Mach 1.
Imagine that all 4,500 Ma of geologic time were condensed into a single 24-hour day. Evidence from the Moon and Mars tells us that for the first few hours of this “day” of Earth’s existence its surface would have been uninhabitable, blasted by an intermittent stream of huge, ocean-vaporizing meteorites. At about 4:00 A.M., life finally gained a foothold. The oldest fossils were entombed in their rocky graves at 5:30 A.M. Gaseous oxygen—pumped into the environment by early-evolving plantlike microbes (cyanobacteria) and then chemically joined with oceanic iron to form rusty sediments known as banded iron formations—accumulated slowly until about 2:00 in the afternoon. Simple, floating single-celled algae with cell nuclei and chromosomes soon appeared, but by 6:00 P.M. they were supplanted by more rapidly evolving sexual plankton. At about 8:30 in the evening, larger many-celled seaweeds entered the scene and a few minutes later so did early-evolving jellyfish and worms."
"We humans arose only a few tens of seconds before midnight. "
If dynamite were brains, you couldn’t blow your nose? Guess not, huh? 
After watching the Discovery Channel for too long, it seems that the standard unit of measure for just about everything is the Titanic or the amount of concrete in the Hoover Dam.
How bout this one? : If Lake Tahoe sprung a leak and flooded the state of Calilfornia to an even depth, that depth would be about 4 inchs.
On how hard drives read.
the read head is a jet flying at supersonic speeds a meter above a pasture counting blades of grass.
(paraphrase of Schulthess)
Doing the math by hand given facts on the web about the volume of Lake Tahoe and the land area of California, I get about 1.47 inches.
Stupid factiod units (pet peeve):
Length:
- “…is long enough to circle Earth X times.”
- “…if lined up end to end, would stretch from the Earth to the Moon and back again.”
Volume:
- Olympic swimming pools
- Local sporting grounds
Energy:
- “Enough energy to power a small town/city/country for X days/years”
In a similar vein you could always check out the Cosmic Calendar made by Carl Sagan. It spreads the history of time out over a year though, not a day.
According to legend, the inventor of the game chess was granted one wish. Supposedly he requested one grain of rice for the first square on the chess board, two on the next, four upon the third one, eight upon the fourth and so on. This represents a total of 2[sup]65[/sup]-1 grains of rice. It has been said that’s enough rice to cover India three feet deep. For the first computer program I ever wrote, I used the standard of a long grain of rice being 10mm. The accumulated length worked out to enough rice to extend between earth and Alpha Centauri (and possibly back IIRC).
If all the cute college girls were laid end to end, I wouldn’t be the least bit surprised. --paraphrased from Dorothy Parker
You forgot the part where the inventor lost his head, because the king was embarrassed by the fact that he could not grant the wish.
[sup]I heard it was wheat and that it equaled the amount of wheat produced from the time of Christ, until 195? (time when the book telling the story was published)[/sup]
IF iditots where like oxen, and rounded up and shot
the world would be a better place
Are iditots the stupid 2 to 4 year old children of idiots??
If the population of China walked past you in single file, they’d never finish. (I can’t guarantee that’s exactly right, but it’s of the right order of magnitude. When I heard it it was 4 abreast, don’t know about that.)
Back in the 60’s there was a Bob & Ray promo for radio that went something like:
“If all the radios in the world were put in one place it would make a noise loud enough to be heard in Lima Peru.”