For Educational Use Only:
WARNING: Jailbreaking an iPad, while LEGAL, voids its Apple warranty and can potentially make it vulnerable to viruses, malware and phishing attacks. Jailbreak your iPad at your own risk.
TP cannot be held responsible for any damage this jailbreak procedure or its improper use or installation can cause on your iPad.
This is for those who've been asking me if there's already a way to jailbreak Apple iPad running on iOS 4.2.
Answer: There's a way to do that. And the procedure also upgrades the iPad's iOS to 4.2.1. You can perform the jailbreak using Redsn0w 0.9.6b4. Redsn0w 0.9.6b4, which is available for both Windows and Mac, is based on the Limera1n bootrom exploit which has already jailbroken all current iDevices for life. The only problem with this jailbreak is that it is tethered, which means that users will have to always reboot their iPads into a "jailbroken state".
Watch this video to learn how to perform this jailbreak:
Here are the files you'll need:
Download iTunes 10.1 for Mac or Windows
Download iOS 4.2.1 for Apple iPad
Download Redsn0w 0.9.6b4 Mac version
Download Redsn0w 0.9.6b4 Windows version