Now that it is legal to jailbreak your iPhone, there is likely to be a burst of new hacks, perhaps even some developed by larger companies for jailbreaking you iDevice. Till then you have JailbreakMe 2.0, an application which can jailbreak you device straight from the browser.
All one needs to do is to visit the website http://www.jailbreakme.com on Safari on your device, and the your phone will be set free!
The application uses a exploit for Safari in order to conduct its no-longer-dirty business, and works with iOS 3.2.1, 4.0, and 4.0.1.
What you’re left with is a freer device and the knowledge that you can install anything on your device now, oh, and also a voided warranty.