Lee, if you organise a grant of $10 million and a modest annual stipend for me, say 250k, I reckon I could have a working prototype in a couple of years. Alternatively, it's got to be a great project for a PhD student in a geography department somewhere...if there are any geography departments left. Thanks for the book reference, which I'll follow up, and the intriguing idea regarding discovery of micro zones. A friend and I wasted a couple of hours playing with Google Earth earlier this year, looking for potentially interesting locations for hardy plants in less well travelled parts of Africa. Even this casual search revealed that there are some super mountains to be explored in Mozambique, Cameroon and across much of North Africa. Plant hunting 21st century style? Best wishes, Tom