Note Ubuntu 10.10 (grub2) is different than Ubuntu 9.10 (grub) .
See http://ubuntuforums.org/showthread.php?t=1195275
To always show the menu,
sudo vi /etc/default/grub
and change
GRUB_TIMEOUT=0
GRUB_HIDDEN_TIMEOUT=0
to
GRUB_TIMEOUT=-1
GRUB_HIDDEN_TIMEOUT=20
Then do
sudo update-grub
which will re-generate the /boot/grub/grub.cfg file.
