[Xymon] State of the art SMS alerting?

Our solution was to send the alerts to a script that formatted a message nicely and uses the Pushover.net API. Pushover sends push notifications to one or several mobile phones. This doesn't help if the internet is down, but we're an ISP and have other ways of knowing if that specific scenario were to happen.

We used to use the email-to-SMS gateways offered by providers but it's foolish if email is down and we also found that those gateways were very unreliable.