Thanks, Baja. I've been thinking about that. A few years back I made one, and everything outgrew it's space way too quickly. I was constantly having to move plants in and out.
On the Sempervivum board there have been some very pretty ones composed entirely of semps. I'd like to do that too, but what I really would love is one with mostly cacti.
If you can get pics of some of your local ones, I'd love to see them!