My parents bought me a great toy last Christmas and I have been using it with my clients.  He's called Ocscar the hamster and he is a chatimal:

When you talk to the hamster he repeats back what you say.  Each time the hamster speaks back, his voice changes.  Sometimes it's really squeaky and sometimes it's a very deep voice.  There are three hamsters to choose from and I believe there is also a Meerkat.

I have been trying this toy out with some of my clients and have had some good results.  Whilst Some of my clients were initially a little scared, some had an amazing reaction to the toy.  One girl in particular could not stop laughing.  She quickly got the idea and had fun saying different words and phrases to the hamster.  Her mum was amazed as her daughter does not typically talk so much (I am working with this girl to help her use the language she has functionally).