How to Jailbreak iPhone 4 on iOS 4.x and iPad on iOS 3.2.x with Jailbreakme.com
Jailbreakers can rejoice again as not only has the iOS4 jailbreak been updated, iPhone 4 users can now jailbreak as well! iPad users are also included, whether you're running 3.2 or 3.2.1, the jailbreak should work for you either way. If you haven't done so already, here's a list of things to do before and after jailbreaking!
And before you proceed, here's the normal disclaimer;
Jailbreaking can and will void the warranty on your device. Should something go wrong, the responsibility is your own, so proceed with caution. If you feel uncomfortable jailbreaking your device, it's probably best if you don't. But if you're okay with all that, read on!