Although this method for Signed Card to Card case was not invented by David Forrest, he improved and released it, and he teaches it on the DVD. (It was invented by Kevin Schaller, but Forrest got involved after the trick fooled him so badly.... TWICE!) As the old magic catalog listings used to proclaim, "It's fun to be fooled!" Well, Xbox fooled me also, and it WAS fun -- neat to know how our spectators feel every now an then.
XBOX is a really, really, really clean signed card to box, without palming -- a gimmicked card case does most of the work for you. (You need to construct the case, using the secret things provided and Forrest's step-by-step instructions on the DVD
In addition to a straight card to box, you can also create a killer transposition effect. I think the best of the three routines taught by Forrest is the transpo -- you show the King of Clubs inside your card box, close the box and set it on the table. Spectator chooses a card, signs it, and selected card is set on the table facedown. You place the box next to the facedown card, and snap your fingers. The card on the table is turned up and it is the King of Clubs. You cleanly show the box all around, then open the flap, slide out one card, and it is the signed selection. No duplicates used.
It is very clever, and will fool you if you watch the performance before learning how this gimmick works -- remember, it's fun to be fooled!
This item is hard to find now, but I have a few I came across in new-old dealer inventory. New and complete.
When the trick was readily available, it was $30 retail, which is a steal for a killer card to case that you will use a lot! But you can get it here for less.
Brand new, with DVD instructions, plus stuff you need to construct the gimmick.