Starting up from a disc image.

[stoid]

Is there anyway to start-up a computer from a disc image without having to first burn it to a disc. I have a PowerBook and an old Ruby iMac. I would like to be able to make a disc image of OS X for the iMac stored on the PowerBook/external HD and be able to start-up from that so that the iMac's HD can be used for media and not hogged up by the OS. I have an OS X image ready to go, and when mounted on the PowerBook, I can get it to mount via ethernet on the iMac, but it doesn't come up in start-up drive options.

[Mechcozmo]

Is there anyway to start-up a computer from a disc image without having to first burn it to a disc. I have a PowerBook and an old Ruby iMac. I would like to be able to make a disc image of OS X for the iMac stored on the PowerBook/external HD and be able to start-up from that so that the iMac's HD can be used for media and not hogged up by the OS. I have an OS X image ready to go, and when mounted on the PowerBook, I can get it to mount via ethernet on the iMac, but it doesn't come up in start-up drive options.

Like a Net-Book kind of a thing? Wouldn't you just choose the network startup option and then choose the OS X disc image?
Or can you not do that, since there is no OS on there?

[stoid]

I tried the Network Boot Disk, and on startup all I got was this big world icon thing flashing. I think that I have to configure something somewhere special to get that to work, and I don't know if it's possible given the circumstances.