If you want cheap-and-easy and care more about temperature than humidity, Munin can be set to send out emails (and, if you know the right email address for your cellphone provider, text messages) when hard drive temperatures cross a certain boundary.

You could probably do the same with Nagios, or even a simple cron job using smartctl.

I've had it come in handy once already when a power bump knocked out the air conditioning but not the servers.

Andrew

--- On Mon, 7/26/10, Ryan Reid ryan@snoot.com wrote:

Using Room alert here: http://avtech.com/ Can't say much about their monitoring software, but the product is reliable.? We use it with SNMP.