First off this needs to be stickied because all of the new Evo owners are bricking their phones.
If you have a new Evo you need to use an alternative method to root your phone!! The old methods and UNREVOKED will brick your phone. Here is what you need to know first.
#1 Software Version: You find this by going into menu/settings/about phone/software info, if you have software 3.30.651.2 or later you can't root using the old method or UNREVOKED.
#2 Hboot Version: You find this by powering down you phone, then while continuing to hold down the volume down button hit the power button. Your phone will load the bootloader and look for the line that says Hboot. If your Hboot version is 2.02 you can't root using the old method or UNREVOKED.
#3 Hardware Version: You find this by going into menu/settings/about phone/hardware info, if you have hardware version 004 or hardware version 003 and software version 3.30.651.2 or newer you can't root using the old method or UNREVOKED. This will break your camera and probably boot you into an endless boot loop. The newer phones have new camera hardware and require the 3.30 software to run and the old method of rooting takes you back to a much earlier version of the software preventing your phone from loading the required drivers thus boot looping and bricking of the phone.
#4 Hardware Version(a): Some of the Version 004 phones are coming with the older software of 3.29.651.#. This means they don't have the alternate camera hardware and can be rooted with UNREVOKED 3.21 and probably the old root method. The key is to check your Hboot, if its 2.02 then use the alternate method.
Now, that you have this information and realized you can't use the old method or UNREVOKED go here and use this method. It should work for you.
[ROOT][GUIDE] HBoot 2.02 S-OFF - Like a Boss Edition! - Updated 11/20/10 - xda-developers
I am not responsible if you brick your phone but this method has worked for everyone with the newer phones. Don't go into rooting blindly, ask questions first so you don't brick your phone. Lets all root safely and enjoy the power of the EVO.
Please Sticky this to save future EVO owners.