Although the other "special offer" kindles have been jailbroken for some time, the kindle hacking community seems to be doing a good job of refusing to (at least for the relative layman) disable advertisements on them or enable any sort of tethering over 3g.
You must have a certain website or subset of the community in mind. I actually got a Kindle 3 a couple months ago and the majority of the discussion that I could find about homebrew on the device was centered around removing the ads. I browsed 4 or 5 forums before deciding it was a lost cause.
In fact, I wasn't even really able to find anything other than removing the ads and changing the screensaver as what you can do after your kindle is jailbroken.
