Hey, Andy. Even with the tethering apps for jailbroken phones, your carrier is able to detect that you're tethering. You'll end up getting charged and it's just not worth the hassle.
This question is for Sharon Vaknin and related to her video "Jailbreak your iPhone, iPad, or iPod Touch".
I want to know once jailbreaked can the iPhone 4S tether 3G/4G on carrier network like AT&T or Verizon without paying extra for the tether feature.