Life In 19x19

I've seen players do this thing before the game where one person will take a small handful of stones while the other person takes a large handful and then they place them on the board to see if either both amount of stones are even numbers, odd numbers, or if there's one of each. What conclusion is drawn from this? Does one player get to pick which color they want? Which player is it?

Here you go.

http://senseis.xmp.net/?Nigiri

http://home.snafu.de/jasiek/rulesfaq.txt

"5.1 Colour Choice

In even games typically the colours are randomly chosen. In
handicap games black receives the handicap stones. -
A manual method for randomly choosing colours is called
nigiri. The older player hides a number of white stones
taken from the bowl, the opponent takes one or two black
stones to guess the parity, and the parity of the number of
white stones is revealed. If the opponent guesses right,
then he takes black, else he takes white."