This is the story of three:
iPhone 3.0.0
AT&T fail
But first:
To thether:
The ability for a laptop or desktop PC to connect to the internet via a WiFi-capable phone.

First, pdanet.
The original AppStore was launched in july of 2008 along with the iPhone 2.0 software. For the first time the small developers had a real marketplace for applications. A centralized hub for selling.
A month or two after the launch of the AppStore an app called pdanet was released. Pdanet had existed for palm phones and blackberry handsets and was an app that allowed for a dead simple way to tether your handset.
Within a few days, the pdanet application was pulled from the AppStore without any explanation. The app was released on the cydia store where jailbreakers were free to install and enjoy.

This is also the story of March 17th, 2009.

This was the day that apple held it's keynote and announced that the newest iphone software would be released. This new software would enable users around the world the ability to tether their phones with the ease of a simple button tap on iphone. People were elated. Everywhere around the world people were happy. Everywhere but in the united states where att would announce at some later date how much extra would be charged to their existing iphone accounts for the ability to tether.
Att was at the time running an ad campaign for their service that allows users to connect to the exact same 3g network at the exact same speed as an iphone 3g but uses a USB dongle and charging an extra fee per month.
iPhone users already pay an additional $30 a month for the unlimited internet service on the iphone, but att would not allow for the phone to tether, no no no. that would be out of the question
Within a few weeks, the friendly folks at had managed a dead simple way to enable this "missing" feature on the iPhone, and the battle was partially being won for the good guys. The next iPhone update plugged this work around, and while the rest of the world enjoyed their free iPhone modem connection, american users languished under the Att money squeeze.

But this is also the story of another Att fail.

So what conclusions do we draw?
It could be said that att knew that the ability for user to buy a $5 application and get online on a laptop anywhere would basically shatter an already extremely fragile network. They simply put pressure on Apple to remove the original PDANet application from the app store.
This undoubtedly caused people to jailbreak their devices to install the now somehow "rouge" application and use their phone as they saw fit.

It should also be pointed out that technically att is not "wrong" in this. They can dicate how much internet you use. Rumor has it that there is really a "cap" on that "unlimited internet" and this has been proven without an official statement by way of att handing out phone bills worth $28,000.00
So beware. It isn't your device. This is what att is telling you. Those that want to tether, be advised that the rumored soft cap (the one they don't HAVE to enforce but can CHOOSE to enforce) is somewhere around 5 gigabytes a month.

Keep an eye on it. I don't tether (anymore, havent for two months) but surf heavilly and listen to plenty of streaming audio all the time.
Can't wait until att calls me and tries to charge me an overage on my "unlimited" iphone data plan.