What do you call the 00's?

Answer 1

The oo's in any century are called "the oughts" followed by "the teens," "the twenties," the "thirties" , etc. "Ought" is another word for zero, zip, zilch, nada etc.

Answer 2

the millenium, or the turn of the 21st century or dawn of the 21st century; new millenia

Answer 3

on the boats it is the symbol for the "rest room" or "water closet" as they call it...the toilet.