After you login to Google Calendar (http://calendar.google.com/) click on the Settings->Mobile Setup Tab. Enter your mobile number and validate your number.
Once done, you can now ask Google Calendar to send Event Reminders through SMS (For free):
This is a fantastic feature and will remind you of calendar events even if you are away from your Desktop and do not have a PDA/Smartphone to sync your calendar.
For MS Outlook users, Google also provides a Calendar Sync feature (http://www.google.com/support/calendar/bin/answer.py?answer=98563) which will keep your Google and Outlook calendar in sync.
Thus, you can now get SMS before any personal or official event :)
