Any suggestions out there on 'swopping' a giant card (as opposed to a jumbo card - for which there are jumbo card switchers etc available))

For example, I perform Behind Bars (11 by 17 inches) - I can either insert the 'jail' card into an envelope and lamely turn it around showing the baddie behind bars ( and cannot show the back of the card ) or...............

Your suggestions are appreciated.

Take a look at the videos Wiz Kid Qua-Fiki made for The Wizards' Journal #16 on "The Three Little Pigs." It is essentially the same trick as "Behind Bars" with a different theme and story, but you may be able to use some of the moves Qua-Fiki developed for the 3 pigs with your Behind Bars trick. Notice that Qua-Fiki shows front and back of all the cards at the end when he makes the pigs and wolf "bow" to the audience.

Extremely good suggestion Jim - and thanks for stirring the memory cells - another idea may be to build a bigger Pighouse (referring to the commercial version) and paint it like a jail.