Installing 3 OS.

[Mike Adolf]

I now have Ubuntu 8.04 and Vista dual boot on one internal drive. I also
have a second internal drive on which I want to put Ubuntu 8.10 but I
want to install it in such a way that my current grub does not know it
is there. When I want to run 8.10 I would like to interrupt the boot
process and reset the boot order to boot first off the second internal
drive on which an independent grub knows nothing about the other two OS.

How can this best be achieved?

Mike