Hey! I see you had the forum posting for the 1024x768 clamshell hack closed at macnn.com. Glad to see you've persisted the info here.
I was researching something unrelated and saw that the method used to trick OSX with that process reminded me of this project. This new process doesn't give us any more features than we've already uncovered, but it does make implementing the old process MUCH easier. In fact, you don't even have to go into open firmware to do it.
As you recall, we were programming the nvramrc area with commands to trick OSX into thinking we had a different card/display installed, thus allowing 1024x768 resolution. I found that typing those nvramrc commands into the boot-command variable achieved the same result. There are only a few open firmware variables available to change from within OSX, luckily, boot-command is one of them.
1) reboot your clamshell holding down opt+cmd+p+r to reset open firmware and erase the nvramrc method.
2) boot into osx (I have osx on an external fw drive. Since we just reset OF, the boot-device is reset as well. So you may have to hold down the opt key during boot to allow the selection of the proper drive/partition to load osx.)
3) open up teminal and type the following (hitting enter at the end of each line):
sudo nvram boot-command='dev /*edit: I just realized that I'm using 2 and have 1024x768, not 1152x768. See my longer code post below in case the extra variables are why.
2 encode-int " display-family" property
4) type in your password and then 'sudo reboot' (without quotes) to reboot
*if you forgot to add mac-boot to the end of it, then when rebooting, open firmware will open up and leave you at the blinking cursor. If that happens, simply type mac-boot and hit return in open firmware to continue on to booting osx. Once in osx, rerun the above command carefully to set it properly.
You should now have the same 1024x768 resolution enjoyed by the whole OF dance of the past. Anytime you want to change things, like for watching a dvd etc., simply keep the above in a text file where you can easily get to it. Open the text file, change the 3 to 2 or vice-versa, then copy/paste it into terminal and reboot. MUCH simpler than playing around with open firmware. I'm sure there's a way to turn this into a clickable apple script so you can just double-click on an icon to change what's entered into the boot-command variable, including automatic rebooting.
I've gone further and played around with changing the card vendorID/deviceID with success and intend on someday finding the elusive holy grail settings. :) I'm sure I can even change the machine model OSX sees from PowerBook2,2 to PowerBook 4,1. If anyone is interested in any of those other paths of frustration...er, I mean fun; if the subsystem-vendor-id and subsystem-id are 0 and the name variable is missing, OSX will go off the vendor-id and device-id only to figure out what the video card is. However, if I omit the name variable, OSX won't boot, so I changed it to what my machine 'thought' the card was whenever I was in holy-grail mode, ATY,RageM3p29s. I haven't touched this machine for a long time, and I'm sure I had changed/removed/bastardized some of the original video kext files. So even though I may successfully change vendor/device IDs, the kext that gets loaded to match has probably been changed by me and isn't working as it should. Your mileage may vary, hopefully for the better. I also don't have any DVD's handily around to check if DVD player works. Core Image and Quartz Extreme are not available with my current settings, so I'm guessing no.
Playing around with video card vendorID, deviceID and name as well as display-family, display-config-info and graphic-options:
sudo nvram boot-command='dev screen
" vendor-id" delete-property
" device-id" delete-property
" subsystem-vendor-id" delete-property
" subsystem-id" delete-property
" name" delete-property
" width" delete-property
" height" delete-property
h# 610 encode-int " vendor-id" property
h# 9c0a encode-int " device-id" property
h# 0 encode-int " subsystem-vendor-id" property
h# 0 encode-int " subsystem-id" property
" ATY,RageM3p29s" encode-string " name" property
h# 400 encode-int " width" property
h# 300 encode-int " height" property
" display-family" delete-property
h# 2 encode-int " display-family" property
0 encode-int 2 encode-int encode+ " display-config-info" property
0 encode-int " graphic-options" property