Before I ask my question: Yes, I did use the search function and that only made me more confused (I read something about third party anysim apps destroying the baseband (1011 error...))....

The question I have is simple: Is it possible to brick a brand new iphone with the following instructions: http://www.iphonegoboom.com/#easy

If it is (and also if it isn't) possible, where can I find a better guide?

looks pretty good to me...its pretty much exactly what i did to unlock my phone (which was on saturday). the ibrickr is used by pretty much everyone and the anysim program was released by the Dev Team. The only *worriesome* part is the name of the site itself!

i was kinda under the impression that you cant brick it with unlock software.. its only software so you should in theory be able to flash the firmware and restore it anyway