Good Idea, but I think you are a little late. I was reading threads on another forum that I visit, and one of the members linked to a company that is already doing it with java moss, and other plants on pieces of driftwood. They say to just throw the piece of driftwood in and watch it grow. I am not quite sure what other framework they offer other than driftwood, but I will try to find the link to that site again and post it for you to look at.

Just a side note, I have seen these in the LFS here in Colorado.