In the Yahoo office in London our resident build manager "Bob the builder" (real name Andy) had a Pilchard the cat (http://www.nickjr.co.uk/shows/bob/pilchard.aspx) which meowed whenever anyone on either side of the Atlantic broke the build.
Clever use of Arduino. I think it would be more useful if it rang when other members of your team pushed stuff to github (or wherever), for the project and branch you're working on.
I'm working on that part. I'm going to setup a Sinatra app that can respond to the GitHub service hook API and which I can then poll from my local box to check for pushes.