Kannel is a pain to configure, but once it's up it will send to urls,
so you can back end it with your favorite ruby web framework.  It will
communicate over the net via smpp, or over serial/usb/bluetooth/etc
with a phone you've attached to the computer.  Finding a phone that
supports sms over serial correctly is another matter.

http://www.kannel.org/

Kannel is the heavy artillery approach.  If you're just trying to let
yourself know a process crashed, I'd stick to email.