I couldn't for the life of me find an I Spy template that wasn't for photoshop (which I don't have), and I couldn't figure out the rack cards to do them on Vista Print. So I made my own on Mixbook, and it matches my guest book that I made there as well. Feel free to visit and use if you would like
http://www.mixbook.com/cards/wedding/i-spy-card-for-wedding-7591978