The listing, Turn iPod Touch into an iPhone instructions only has ended.
I could show you how to turn your iPod Touch into an iPhone, down to the texting and calling apps, but it does require you buy something for like $68. I can also teach you how to get GPS and siri on it, and you'll be able to use your own phone number to text. It will make your iPod Touch (4th gen only) even look like an iPhone, but the size will be different. It even has the vibrating function, and comes with a little apple logo sticker to put on the back to make it look even more like an actual iPhone.