Back in 2001 or so, I was studying in a college in another city, and traveled back home during breaks and on some weekends. On one occasion, I took a Knoppix mini-CD with me, repartitioned the hard drive on my mom's computer to cut a small ext2 partition for myself, installed Knoppix (there was a script to install it on HDD), set grub timeout to something like 1 second so no one would ever notice, and enjoyed my very own hidden Linux every time I visited home.

I'm pretty sure that if I manage to find that HDD, it will boot today.