Malte, some work of our students here at Sydney might help:
http://www.weg.ee.usyd.edu.au/projects/det_ug2003
Title: Web Based SMS Notification Service using Open ACS
Author: Jackson Chung Kit Chow
Jackson modified notifications to handle SMS. Basically he added SMS as a notification mecanism within the package (it was actually neat simple as he implemented it using service contracts). I can't remember the full details, but I personally tested it in Sydney with an SMS modem and it worked really well.
Moreover, there's another interesting package that "filters" information from different RSS sources and could use the notification package to generate instant annoucements: say you want to be notified if the subject of a particular source news is 'SCO goes bankrupt', so as soon as that happens, you are immediatly notified by whatever mean (SMS/Email/etc) you have selected.
Title: Market Intelligence platform
Author: Kim Hoan Tran
I hope that helps
Ernie
