a while back I came up with a "new" method for obtaining duplicate signature.
I posted the method on www.themagiccafe.com,
it is in the secret session (for those who have more than 50 posts on that site, you are welcomed to check out that thread.. the topic is "New way to use duplicate signature???? " )
basically, the problem with duplicate signature is the spectator will recall signing their name on the same card beforehand, so the magician can't use the duplicate card in the same show as he might risk being busted as the spectator might remember the card.
here's a copy of my post
"here is how it goes.
start off by doing some stupid signature matching tricks (have 2 spectator.
Bob signs his name on the face of a card (an Ace of hearts), Staci signed her name on the BACK of another card (Queen of Hearts).. blah blah blah.. you then do a double lift, show that their signatures are both signed on the same card. here is the KEY, Staci would think that she signed her name on an ACE OF HEARTS, but the truth is, her signature is on the back of a Queen of hearts.
NOW, you got yourself a duplicate signature, one that the spectator will never remember because even if they remember signing their name on a card previously, they would remember it was a DIFFERENT card.
you then load your signed Queen of hearts into your sock later on that show (about 7-8 tricks later), force another QUeen of hearts on Staci once more, have her sign her name on the back (Don't let her stare at her signature for too long, as you know, the signatures will not be 100% pure match)
blah blah blah, lose it in the deck, steal it out, then you put your feet up, have her grab your ankle REAL HARD, make sure nothing goes into your shoe.
you spring the deck onto the bottom of your shoe..
take off your shoe, take off your sock,
the card is now INSIDE your sock.
apparently it has penetrated through both your shoe and your sock.
or, you can load the card anywhere you want.
card through window comes to my mind right the way
with this method, you can use your duplicate signature in the same performance instead of waiting for a few days to past in order to "erase" the spectator's memory.
I hope y'all like it"