I just got a 16gb wifi ipad2. I also have att iphone3g with unlimited data. My wife has a iphone 4 with 2gb monthly limit. Both lines are on att family plan. I would like to know how I can get enable tethering to get internet access on my ipad2 when I am outside traveling. What do I need to do and is this something that will add cost on a monthly basis or something that I can turn on and off when I need it. I wont need it much, mostly ipad will be used in the house, but for times when outside.