If you don't live in American, technology is a wonderful thing. You see, in Canada, if you have an iPhone, you can tether it to your laptop for free:
Of course, if you live in America, you can't use an iPhone without having an expensive contract from AT&T. Which means not only do you not get tethering, but you have to listen to AT&T Executives lie year after year that it's coming "soon."
Unlike in Canada (and other parts of the world where people have phone companies that don't hate them), AT&T normally charges an extra $30 a month for tethering. That's a huge rip off, but at least if you have a need for tethering, you might bite the bullet. But AT&T won't even offer that crappy deal to it's iPhone customers (it's most profitable base). Why?
Well, probably because AT&T has this big pipe dream for tiered pricing, which it also says is coming "soon." But customers hate the idea and AT&T hasn't been able to convince other carriers to come aboard in forcing it down American's throats. So better to prevent customers from being able to use their products, than let them get used to the idea that things shouldn't cost extra for no reason.
When will AT&T finally come to its senses? Probably too late. Only after it has real competition, and by then it will have antagonized so much of it's most profitable customer base, it might not survive.