The stamp set is called Festive & Fun, it is in the 2011 Holiday Mini Catalog. Only a couple more weeks to purchase products from this catalog. Anyway, the gift card holder is actually a A2 envelope that's folded in 1/2. You cut one side of the flap off and stick the other side down to form a pocket for the gift card. Clever, eh? I can not take credit for this idea...it has been around for quite awhile. Here is a picture of it open--
Happy Stamping Friday!