I have an external disk (usb/firewire), with 1 working leo, 1 tiger and 1 partition for installers. I like to see all the installers (zephyroth, iatkos, kalyway, eddie11c, XxX, tubgirl...).

I use the retail dvd 10.5.0, apply the efi bootloader for that partition and copy mach_kernel (toh), dsmos, AppleNforce..and delete Appleintelcpu,,,finally patch with marvin the partition. Don´t forget once the install finishes you need repeat the steps with the new install (copy kernel,dsmos....patch with marvin).