We have three so far, and I'm contemplating at least one more.
The above stamp goes on the bottom (or inside, by request) of each of our crates.
We have a "Thank you for your order!" stamp with our url and a picture of a stack of books.
We also have a stamp of Africa with a heart over Ethiopia. This was not a custom stamp, just one that was in the shop we were ordering. Since the proceeds from our shop go towards the adoption of our daughter from Ethiopia, we thought it appropriate to buy the stamp.
All of our stamps were made by Kristina of HappyRainyDay, and we are beyond pleased with her work.