Oh, that's something I have been planning to do for a long time now.

I saw those Furby things quite a while back, then looked at a cat, and then a small dog, and thought to myself how to make a robot pet from this combination that people can touch and interact with. My plan is to use capacitive sensing underneath a soft fur-like outer skin and put heat sensors, cameras, tilt sensors, microphones, speaker, head/neck/limb/etc movement motors, etc. and with some clever software it would become a companion for children/house-bound people/the elderly/etc.

Now all I need is the time to devote to this project of mine.

Oh yes. I had this crazy idea after I adopted a stray cat a few months back.

What about a robot mouse/furry animal that a cat actually finds interesting? (Dogs will get along OK with a ratty old tennis ball, so there's obviously no market there .

Admittedly the animal in question is a little on the psycho side after bringing itself up living off rainwater, grass and birdseed, and living under people's houses for the first 3 months of  its life, but after buying all the guaranteed-to-be-good cat toys down at the local pet shop and supermarket, I've found most were good for 5 seconds of pawing and mouthing, and none have been touched since.

The most successful toy to date has been a toy mouse on a string that obviously  has a sealed-in speaker, battery and switch and squeaks when chewed, bounced or clawed. This item sees daily use.

But something that scampers along the ground, is pretty rugged (one of my slow-moving beambots was crushed to death in a few seconds), and does things cats find interesting (e.g. the toy must drag something like a long, brown shoe-string along the ground behind it might actually be a saleable item.