PS3 Debug Firmware 2.36 appears to work at least on any phat ps3.
My ps3 is nothing special, just a phat 80gb non-bc model.
I am running an NTSC-U console, and I do not know if this would work on a pal console, or any other region.
[ame="http://www.youtube.com/watch?v=cn52Ol-HAoE"]YouTube - Ps3 Debug FW 2.36 on retail![/ame]
WARNING: DO NOT USE DEBUG 3.41 IT WILL RSOD