As far as I know there is a boot logo which is shown when the kernel starts loading (only supported in newer kernels). On my Mandrake distribution it shows a little tux. That's what acid_kewpie was talking about.
But it is also possible to get lilo to show a graphic screen when booting. Which is a graphic with the text welcome in lots of languages on Mandrake. The following link might help you out on that:
http://hints.linuxfromscratch.org/hints/bootlogo.txt