I have three SATA disks in my system. The first disk has Windows XP on it, the second disk has my Linux system on it, and finally the third disk has Mac OSX Leopard set up with a GUID partition.
The system boots using GRUB 0.97, and the GRUB menu is on my Linux ext3 partition. This is the menu.lst file for my system:
# GRUB configuration file '/boot/grub/menu.lst'.
# generated by 'grubconfig'. Sat Apr 11 19:52:24 2009
#
# The backup copy of the MBR for drive '/dev/sda' is
# here '/boot/grub/mbr.sda.3725'. You can restore it like this.
# dd if=mbr.sda.3725 of=/dev/sda bs=512 count=1
#
# Start GRUB global section
timeout 15
color light-gray/blue black/light-gray
default 0
# End GRUB global section
# Other bootable partition config begins
# Mac OS X
title Mac OS X
root (hd2)
chainloader (hd2)+1
# title Windows on (/dev/sda1)
title Windows XP
rootnoverify (hd0,0)
makeactive
chainloader +1
# Other bootable partition config ends
# Linux bootable partition config begins
# title Linux on (/dev/sdb1)
title Slackware Linux
root (hd1,0)
kernel /boot/vmlinuz root=/dev/sdb1 ro vga=normal
# Linux bootable partition config ends
title --- For help press 'c', type: 'help'
root (hd0)
title --- For usage examples, type: 'cat /boot/grub/grub.txt'
root (hd0)