How can you achieve a 30 seconds delay before your system boots to the default kernel?

Lilo -d 30--d delay if you have specified several kernels, and press shift at boot time, the boot loader will present you with a choice of which system to boot. after a timeout period the first kernel in the list is booted. this option specifies the timeout delay in deciseconds. sample configuration of /etc/lilo.conf prompt timeout=20 default=linux boot=/dev/hda map=/boot/map install=/boot/boot.b message=/boot/message linear image=/boot/vmlinuz-2.6.9-5.el label=linux initrd=/boot/initrd-2.6.9-5.el.img read-only append=rhgb quiet root=label=/