There's lots of information about the old Furbys but not much out there about the new, 2012/2013 model that everyone will be getting for Christmas.
Ours was completely unresponsive after less than a week. We thought it was out of batteries so we replaced those and it was still dead with a fresh set of batteries.
The older Furby models apparently had a reset button. We couldn't find any reset button so I thought I'd try another trick of the old Furby models - hold down the Furby's tongue while you put the batteries in.
Our Furby bounced back to life with a weird dance. The bonus, in our case, is that this completely reset the Furby's attitude and personality. Instead of being slightly valley girl'ish ("Like OMG, no WAY?!"), our Furby is now a burping, farting, beat boxing little weirdo - which is much more in tune with what I want for my boy's playmate/toy.