I'm not entirely convinced that the Balldo™ is going to take the world by storm in the way the makers are hoping for.
(NB: some content on their web site is Not Safe For Work. That being said, you really do need to visit their web site to get a proper sense of just how uncomfortable that thing looks. You may feel the need to scrub your web browser history afterwards, is all.)
For what it's worth, the Wired review describing the Balldo as "less of an erotic toy, more of a dadaist interrogation of the very concept of pleasure" is well worth a read.