me too follows the same path as yours.
installing 1st distros in MBR and then making entry into its grub.conf about the rest of distros ( without installing there bootloaders anywhere ).
but i always faced a problem with this methodology.
suppose my 1st distro, whose bootloader is in MBR, fails.........then???
it won't allow me to access rest of the distros.
the only solution seems to have is to restore its bootloader again using its 1st cd or through rescue floppy.
i fired a query on this issue few days back, but can't understand the solutions given to me
you should have a glimpse on that here
could anyone able to understand that...plz. explain a bit to mee too.