I'll third the Nagios suggestion.

We do SMS alerting from our Nagios server using a rather Heath Robinson setup, that works fine >:o]

There is a Nokia 7110 mobile phone plugged into the back of the server using a serial cable and then use GNokii to send the SMS messages from Nagios.

Hope that information is useful to you.

Too bad you aren't using any of the CPAN solutions for sending SMSes, like Device::Gsm.
But beware, I am the author of that mess... ;-)

Thanks I will take a look at that site.

I guess I was really thinking of an outsourced service that would just send us an SMS. We could then just get a web enabled mobile phone and be able to restart the server whereever we can find a hotspot.

I've no good experience with an outsourced service monitor, but I heartily second the recommendation of Nagios. I use it to monitor servers both here in the office and at remote locations, and after much configuration and some customization I've got a system that I cannot imagine being without. The only additional cost of adding more machines is that of my time to add it, usually by copying an existing configuration and editing it just a bit. No monthly bump, no repeated conversations trying to get proof that the voice on the other end of the phone is connected to a brain, no waiting for simple changes such as adding another recipient to the notification list.

#!/usr/bin/perl
use strict;
use warnings;
use Net::SSH::Perl;

# Net::SSH2 is even easier than this

my %hostdata    = (
        'localhost' => {
                           user  => "z",
                       password  => "qumquat",
                       cmdtorun  => "ls -la",
                      misc_data  => [],
        },
    
   'zentara.zentara.net' => {
                               user  => "z",
                           password  => "aardvark",
                           cmdtorun  => "/usr/bin/uptime",
                          misc_data  => [],
        },
);

foreach my $host (keys %hostdata) {
    my $ssh = Net::SSH::Perl->new($host, 
                       port => 22,
               debug => 1,
               protocol => 2,1
                );
    $ssh->login($hostdata{$host}{user},$hostdata{$host}{password} );

    my ($out) = $ssh->cmd($hostdata{$host}{cmdtorun});
    print "$out\n";
}
[download]

This snippet was posted awhile back, I can't find the original node now so I post it