Is there anyway to do this? I'm not at home and I want to install OS X on my Macbook (currently using XP) and I'm not going to be home for a while so a friend let me use his disc but I got a message saying I can't install Leopard on this computer.

Is it still possible?

If you are talking about the gray disk's that came with your friends Mac, then the answer is no. Those disk's are only for the Mac that it came with.

You probably have the OEM disk. Which works with one Mac only.

which sucks.

Not necessarily.

Weirdly enough I got a gray 2008 mac pro install disc to boot into the installer on my macbook.

I have also bypassed it by booting into the installer using the computer the gray disc came with, then installing to an external drive and then bouncing that image back to a HD on a different mac pro. Works fine.

Of course you can install it to an external hd and then restore the external hd to your Mac, but he wants to know if you can use the gray disk to install and the answer is no.