Anybody tried topsy turvy tomato planter or made their own?

I was wondering if anyone has tried the topsy turvy tomato planter?

I was also wondering if anyone had any clever ideas how to make an upside down planter like the one advertised? Seems to me that it would be relatively easy to make. It can be used for more things than growing tomatoes too.

Any input would be appreciated.

I know that we have a great deal of clever people on DG so throw any ideas at me.

Thanks

Elaine and Otis