I've just seen these on a German orchid site (
Roellke Orchideen).
They are like clay pots but you mount your orchid on the
outside. You pour water into it and the clay wicks the moisture from the inside to the outside. They even suggest you paint the surface with moss spores so that the whole thing becomes green and lush.
Here are a couple of photos from their site.
Has anyone ever seen anything like this? It just strikes me as an amazing solution to having mounted plants but not having to worry about watering them every day!