HeartBeat
A HeartBeat in the computer world is a regular (every second,minute,hour) signal or pinging of a system or service to ensure it is still running.
For example you could set up a CronJob of
wget http:<yourhomepage>
to run every 10 minutes and then send you an SMS you if your ISP was down !
See http://dictionary.reference.com/browse/heartbeat
HeartBeat (last edited 2008-08-06 16:27:20 by localhost)