We use the "good old" pager which has some advantages:
- it works always, doesnt matter where you are (in switzerland indeed) - you dont forget you have pikett ;-) - you make clear who has pikett (as long as you have it, you have pikett) - you hear it (even your neighbors can hear it :P)
but for sure, there are some disadvantages:
- its kinda big - yet another device
Our alerting system goes over a Siemens GSM box linked with serial to a server. Works like a charm ;-) And for the pager you can simply send SMSes, just keep in mind you're limited to 80 chars on the pager.
Pascal