Binary package “watchdog” in ubuntu lucid

A software watchdog

 The watchdog program writes to /dev/watchdog every ten seconds. If
 the device is opened but not written to within a minute, the machine
 will reboot. This feature is available when the kernel is built with
 'software watchdog' support (standard in Debian kernels).
 The ability to reboot will depend on the state of the machine
 and interrupts.