That would be amazing to see work! It's always cool to have some sort of fun way of growing your plants instead of the old dirt in a bucket thing. I think you should give it a go and see if it works. I know that plants operate almost entirely off turger-pressure and from the looks of it, it seems tomatoes grow even faster upside-down for this reason. Gravity causes the plant to draw in more nutrients. I have seen one of those upside down tomatoe growers at ACE for about 15 bucks, maybe that would be a good idea to have the roots upside down and set up a timed mister on the top for feeding. You should give it a go if you ever have some extra cash lying around, it would make my month to see that work!