Its really a nifty feature, now we can receive SMS alerts from Google Calender. Its a nice feature, and its really cool since it even works for a small country such a Maldives. Presently this feature only works for Wataniya subscribers. You can even import the calender from your outlook or iCal into Google Calender as well.
You can set up an appointment and Google will send you a reminder alert before the appointment or you can set birthday reminders, etc. Here is a tutorial on GoogleTutor