Something really fun I found out recently, when my friend lost all access to his system except for a single WebDAV share by accidentally turning off all his remote admin access:

If you write “b” to /proc/sysrq-trigger, it will immediately reboot the system (like holding down the reset button, so inherently a bit dangerous).

He was running Nephele with / mounted as the share, so luckily he just uploaded that file with a single “b” in it, and all his remote admin stuff came back up after the reboot.