How to make a mac appear as a mountable hard drive to another mac under OS X?

Connect the two Macs using a firewire cable, then restart one of them and hold down the “T” key. The Mac will pretend to be a firewire hard drive.

Yup!

boot up the system you are ‘driving’ first while the firewire is plugged in then power up the second one while holding down T

FYI it’s called target disk mode; make sure you fully unmount the drive (I’d drag to trash) when done before powering down that disk (jist hold the power button down til it shuts off) or else you run the risk of potentially damaging the master directory block

Ahh the power of T- it’s amazing everyTime!