Subzero (free pimpage!) asked why 55 had come to be known as Presto. And to be honest I had no fawking clue. So I figured pocketfives.com would probably have the answer and they do.
"It seems that for many players, especially online players, there is a mystical aura surrounding this hand that somehow makes it special and gives it a better chance of winning."
"Presto" is used Blackjack and poker players wanted a hand to call Presto too. 55 was seemingly chosen in a somewhat random manner. Not too glamourous an explanation ...
However Kent has pointed me to Cardplayer that elaborates a little further:
"presto: 5-5. Comes from what one says when revealing a pair of fives as one's holecards. The term was coined at BARGE and evolved from what a blackjack player says when turning over a blackjack. (BARGE is Big August Rec.Gambling Excursion, an annual Las Vegas convention of online poker enthusiasts. RGPers - those who read and post on the Usenet newsgroup rec.gambling.poker - have used the term presto as an identifying catchword.)"
The bottom line: Presto is Gold and you all know it!