ping:
Every server gets pinged every two hours. If one package gets lost, that server's ping condition will change from 'green' to 'grey' or from 'grey' to 'red'. If a ping gets through, condition will change from 'grey' to 'green' or from 'red' to 'grey'.

load:
Every server's 'uptime.cgi' gets checked every four hours. The 'load' is calculated by getting the average of the presented 'load averages:' values. this value will be added to the last known load value and that result divided by two gives the new load ;-)

users:
NewUsers = (2 * OldUsers + CurrentUsers) / 3

To join, simply put the following script on your web server and mail me the URL together with the location of the server.

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#!/bin/sh
echo "Content-Type: text/plain"
echo ""
uname -rsm
uptime
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If you don't want a big apache on your server (might be a mail server), send me a message. There's another very small solution for your inetd.