An iPhone. The iPad and the iPod can't make regular phone calls.
ipod shuffle
it means that YOU are the controller of it. "I" refers to whoever owns the iphone, ipad, or ipod. so in other words, its YOUR way to control it how ever you want. (also iPhone, iPad, and iPod sound and look better then youPhone, youPad, and youPod)
internet
iPhone/iPod Touch/iPad iPhone: 1G, 2G, 3G, 3GS, 4 iPod Touch: 1G, 2G, 3G iPad
Yes. The home button on the iPhone (and the iPad) is bigger than the iPod touch's (and the iPad Mini's)
no, you can't, but you CAN put ipod touch/iphone apps on your ipad
Yes and it is better than ever. It is free on the IPod, IPhone, and IPad. So what are you waiting for? Get it now!
iPad
Probably iPod touch, iPhone, iPod nano, and iPad.
Many apps will work on the iPhone, iPad and iPod Touch. Some are written just for the iPad while others only work on the iPhone and iPod Touch. Under the title in the App Store it will specify which devices the app will work on.
Its a hack for your ipad ipod or iphone