One day I'll get the agents loaded on the machines so they can just page me

Or at least get everything onto one screen. One of the companies I'm involved in, BaseN, is selling network monitoring and performance measurement services based mostly on SNMP. But their system can show pretty much anything on the same screen, with alarm limits - so I actually abuse it to monitor machine room temperature, line voltage, house heating... and of course every single SNMP-monitorable parameter of all my systems. So I have stopped looking for red lights on the devices themselves