I'm a baker so I usually separate eggs by cracking them into the palm of my hand and then I let the whites funnel through my fingers... but I know some people don't like to get their hands dirty so here's a nifty trick for separating eggs that will keep your hands completely clean. 

Start with an egg that's sitting on a flat surface like this plate - you want the yolk to be sitting up a little higher than the white (I watched someone on TV try this technique with a big bowl full of eggs and it failed miserably.  Why do they let people who obviously never step foot into a kitchen attempt this kind of demonstration on live TV?). 

I digress.  Okay - so what we want to do is take a clean water bottle and basically suck the yolk up into it by giving the bottle a little squeeze before going in for the yolk.

It's working... check it out!!

There it goes.

Cool, right?

Yepper.  Super cool.  Now give the bottle another little squeeze to get the yolk out.

Ta-da!