Ned Heite suggested:
>Put your world in perspective. Go to:
>http://antwrp.gsfc.nasa.gov/apod/image/0011/earthlights_dmsp_big.jpg

Definitely perspective!

I just got through teaching first graders about fruit fly reproduction and
how if they went crazy and didn't die or decay for just one year, a single
pair would lead to enough progeny to create a ball of fruit flies
96,000,000 miles across (10\41 fruit flies).  Of course the difficult part
is getting the concept of a mile across to kids that young - almost as
tough as teaching metric to grad students.

        Dan W.