There is a company out there that sells these reversible turntables that are round on one side and rectangle on the other and I can't find them, they are suppose to be priced really good.
But it's Chilton industries or Chilton Inc. if anyone can find the link for them can you post it here for all to find.
It came up #2 on a google search: www.marilynchilton.com
(edited to add: if you search for "chilton turntable".)
The cake wheel looks to be more versatile: www.cakewheel.com
Here is a link directly to where the turntables are:
(it is from the link posted above by the PP)