I love this concept, so I'll probably be using it again. I actually have some boxes left over from other projects that would fit a set of these beautifully. It's also something that's easy and you can use a variety of different techniques, so I'm thinking it would be a great workshop card or set!
I also made this card, which is a concept I had in my head from the minute I saw the stamp set. It's been modified a bit from the original concept I had in mind, mostly because on different days I have different tastes! The inside says "peace love happiness" (I suppose the outside does too, just in a different language!). I think I know who's getting this one too, but I now have two cards for them for the same reason, so I might just put this one for sale after all.