I rooted my Evo 4G about 2 months ago using unrEVOked. After it rooted I installed the root apps I wanted, etc. but when I tried adding ROMs to the device, it wouldn't allow. I tried Googling the problem and came upon a few forums and blogs where people claimed that since unrEVOked roots the device, they have no real way of knowing how they did it and the guys at unrEVOked aren't leaking their secrets either so it's impossible to flash ROMs to the device. Two ROMs that come to mind that I wish to flash are: Baked Snacks and some Android 2.3 ROM that is stable enough for my device.