Back in the olden days of the early 90s, as a cabal of geeks laboured at the National Center for Supercomputing Applications, little could anyone have imagined what extraordinary feats their fledgling "internet" might one day achieve.

Feats like, say, a little man showing his bum-cheeks to your mate in Sydney. In real time!

The bum-cheeks are just one (well, two) of the secret emoticons known to many a Skype Chat veteran, but still a mystery to most newbies who are still getting their heads around the whole free phone calls thing. (Yes, Mum. You can close your mouth now.)

You can find out what other Skypers are saying about these Easter Eggs on the Skype forum, where the bare bum and the one-fingered salute appear to be the most popular hidden gems.

So, how do you slip one of these babies into a Skype chat? In most cases, just type the appropriate word, contained within brackets. So, just as when you type ':)' you see a yellow smiley face in your Skype window, you'll see the mooning man if you type '(mooning)'.

Mess around with other Easter Egg prompts, from '(finger)' and '(ninja)' to '(headbang)' and '(toivo)' (that's the butch bloke and his dog), and you'll create seven shades of confusion among your Skype pal as he or she tries to figure out exactly what it is you're trying to imply.