Squiggly is a calendar and location based app that can silence your phone. You know what the best part is? It knows where to silence your phone even without you telling it. Developed by my.app.factory.
Update: An updated version (1.4) with much better location awareness and calendars functionality has been released to the Play store. Get it now! Don’t forget to look at the location types available for you to choose in Location Sentry.
Update: v1.4.2 coming soon with local calendar access for ICS and above devices. Watch out for the update on the Play store in the next few days.