If you are looking out for an eye-catching coffee table, you might want to consider getting this soaring one.
Inspired by the UP cartoon film by Disney/Pixar, the table looks like a glass slab being floated or soaring up via helium balloons underneath. I do believe the picture explains itself. It being a table, it won't really float up naturally, though you could always get helium balloons and a piece of styrofoam board to create a 'working prototype'.
It costs $3,800 USD, and only 20 has been handbuilt. I would think it is quite sturdy, though it does look a little weak, and there's a slight fear that the stem of any balloon will just break off. especially those at the four corners.
You can get more info here