Sometimes it's useful to have a console permanently logged in. That is without the usual username/password prompt. Naturally you are relying on just physical security here.
Edit /etc/inittab and find the lines like this:
3:23:respawn:/sbin/getty 38400 tty3
Change these to:
3:23:respawn:/sbin/getty -n -l /usr/local/bin/autologin 38400 tty3
That's it, nice and simple. Just ensure that you have a unique ID (the part before the first colon) and you've specified the correct terminal at the end.