All this *might* allow is access to the developers private network, which doesn't have enough people to play games on anyways, doesn't allow access to the psn store, and will just result in pissing off developers who will complain and get your asses banned. Don't bother.
STOP! Before you ask questions... READ the first post! RTFFP = Read The F*cking First Post
Yes, A 3.55 "jb" (cfw) is available, no >3.55 "jb" or cfw yet.
Yes, A 3.55 downgrade is available. But not to lower than stock firmware! (What it came with)
No >3.55 downgrade is out there yet.