So without thinking, I put iOS 6 on my iPad 3 and now it won't activate!
What do I do!?
really?
99% unbrickable. Only the iPhone 2G could be bricked by an end user. And that only was a small chance if the end user used ZiPhone to jailbreak their iPhone because ZiPhone was based on a buggy/incomplete Pwnage exploit. Members of the iPhone Dev-Team and other elite iOS people could brick an old bootrom 3Gs or older device. But they'd have to be wanting to brick it. redsn0w and other jailbreak tools are not able to brick a device. All "bricked" iDevices are able to be restored via DFU mode, unless it has a hardware problem.
i hate the misconception that your phone can be "bricked".
Misconception? would you deny that flash memory has a limited life span? Would you deny that users who chose to install the iPad baseband on their 3GS ran a real risk of "bricking" or frying their 3GS? I'll grant you the risk as a rule is slight, but none the less there is a real, if slight risk.
You can't brick an iOS device. Put it in to DFU mode (Google it) and restore it to iOS 5.1.1. Only use iOS 6 if you are a registered developer and your device has its UUID registered with Apple.