Do you mean you want to use it for something other than tomatoes, Charlynn? The sky's the limit in that regard. At Mass MoCA in North Adams, MA, they have full-grown trees planted upside down. It seems like a form of torture to me, because the trees are clearly trying to right themselves, but it can be done.
Thanks for the answers, but I'm still hoping for more ideas.
Make sure you have it on a strong support as it will get quite heavy. Use a really good draining soil mix for the bag. Fertilize often with a lower dose. Wind and direct sun on the grow bag itself are not your friends.
Charlynn B, my tomato plant grew quite well as long as I watered it.
Then I saw a bird made a nest in the topsy turvey thing & I quit watering it.
Needless to say it didn't grow well at all with no water.
Topsy was hung under a pergola which gave the tomato both some sun and some shade. I think the tomato likes sun and maybe a little shade.
I plan to do it again this year - very soon.