I recently ran into this:
Here what this “toy” can do:
https://www.youtube.com/watch?v=DQyfAWCRj7s
You can communicate with each rabbit using a REST API and a cloud ! 
With new embedded 32bit processors anything is possible. Cool toy!
Source code of previous generation has just been released to the web:
[url]http://code.google.com/p/nabaztag-source-code[/url]
Unfortunately a lot of it is in french. But still one can find interesing things there. It contains both hardware and server side source code.
This is/was an interesting product - the oldest one wrongly managed by its parent company. At least the previous version that was released as open source.
As far as I understood, tthe company that initialy created and maintained the nabastag was never able to make any profit. Most of the interesting function of the bunny were not done by the bunny itself, but by centralised servers (including speech synthesis). Recently, they just disconnected the server (that was poorly working anyway…), and the owners of the previous “bunnies” just ended up with a dumb terminal, with no server to connect to, basicaly just a useless plastic toy. They released the server side software as opensource just telling the communauty “try to make it work yourself”.
Hopefully the company that released the new version will have learned from the previous mistakes… At least in France hardly anybody wants to buy the new one, after beeing screwed by its ancestor 
That’s bad because that was not a bad product !
So buy a toy, but connected to a server or a cloud, you are still connected to a “proprietary” something that may be working now, but who knows in one year ! Like modern computer games…