The euro is probably the only currency in the world that issues banknotes with a face value of zero. These are collectibles and there are hundreds of different designs, but they are genuine —although unofficial — banknotes with real security features like holograms, microprints and UV ink.
At present there are over 5,000 unique designs. They typically cost €2. I think that they make great souvenirs — much better than postcards, t-shirts or tacky items like snow globes.
I've been...