both ipod and ipad can be used as a "phone". you need to download a free app (e.g. Talkatone) from apple store and then you can make a free call anywhere in Canada and US. To receive an incoming call, it's a bit complicated. You have to apply for a free phone number from IPKall for your Ipod or Ipad. The only difference between Iphone and Ipod/Ipad is that you have to stay in a wifi environment (e.g. library, cafe, airport) or any wireless environment (e.g. wireless router in your home) for the internet connection.
I can use my ipod to make or receive a call without any problem.