Well I just put one card in one specs hand (say the 10c) and another in the other specs hands (say the 6d), and ham up the patter about something mystical about to happen & get them to turn over their cards. They've swapped places. Maybe this is the David Blaine effect referred to by others above, I don't know - I just know what I do(!)
I have to say, in almost heretical fashion on magiccafe, that I find red hot mamma too long and indirect. But I haven't tried it real world - just in the privacy of my garret; I recognise there's enough praise from all sorts on here raving about it (usually high up in peoples' top 10) to realise its a real worker. Just not to my taste, that's all

Rope a card for sure.

There are many great things possible with a duplicate card. Just make something up. The "here then There" ellusionist crap is really just a transposition in a spectators hands (it's a great trick but ellusionist ripped it off). Many transposition tricks are possible.

Try brent braun's "kickback transpo" from his DVD... "Decks, Lies, and Videotape". It's one of my favorite tricks with a duplicate because the card the transposes is face up the entire time. It almost changes when you blink. It's a great use of some Marlo ideas.

Also I believe Derek Dingles torn and restored uses a duplicate. It's out of the book The Complete Works of Derek Dingle. I could be wrong though.

Troy Hoosers got some ideas about duplicates... try DesTROYers... by Joshua Jay



I second the Paul Harris effect.. it's a great one and still prominent in my repetiore. John Guastaferro's "Tailspin" is a great routine that utilizes The Bizzare twist in which there is a lot of magic done with the spectators signed card, before the color is changed. It's in his L and L video Brainstorm Vol. 2

Expert Card Technique has an entire section on stranger cards... check that out...it's great stuff.

Good luck

Derek Dingles Card Assembly.
It is like a coin matrix with cards. It requires one jumbo card(the cover card which could simply be a piece of cardstock), and a duplicate card.