Hide-show grub menu at boot
The default installation of the GRUB boot loader by Fedora 13 set the timeout value to 0 which effectively hide the GRUB boot menu from the user. To activate the GRUB menu at boot time, set the timeout parameter to a non-zero value in the file "/boot/grub/grub.conf.
To hide the GRUB menu at boot time, set the timeout parameter in the file "/boot/grub/grub.conf" to zero.
The timeout value is the number of seconds the GRUB boot loader will wait for user input before it boot the default OS.