CVTSA [ClairVoyant SysAdmin] is a tool for GNU/Linux written in C that allows a user to run any command he wants on his Linux box [according to his permissions on that machines] even if he is far away from the computer. CVTSA works as a shell but receives commands via email (email could be sent from a standar mailbox, from wap or GPRS or some societies services that allow to send emails as SMS, etc...). There are some security features that make CVTSA quite safe.