Here's the real kicker: There is no way to keep an unlimited data plan and add tethering any more. So, I say bollocks to that, everyone use their minds, and take what we are entitled to with out further rape from the already huge and wealthy conglomerate AT&T. Jailbreak the iPhone or mod the android, tether for free.
What I want to know is how does the carrier even know? Unless it's something built into the software.
A friend of mine says tether costs extra on her plan on Vodafone here in the UK, but she uses the Wi-Fi hotspot feature in Android Froyo without any problems - it all just counts towards her data usage.
Yup, I work for a similarly stupid big business. Completely different product, but when the economy went to crap, they said "we are not making any money because people aren't buying - so we need to jack up our prices for those that are to cover ourselves"... all the while, our competaters were getting all of our old customers... who puts these idiots in charge? If you make your products more easily available and attractive - more people will buy it, and you will make huge profits in the long run. it's a win-win. No brainer right? Well apparently these execs don't have brains.