I can launch Google Maps, Mail, Safari and others... but is there the same functionality for Calendar??
EDIT: I only want to add an event into the calendar.
All those things you mentioned can be easily used to launch the application and go some where:
But with the calendar the only real thing you can do is add an event. If this is what you want to do, I think you can just do either of these two suggestions:
start your URL with ical://www.somesite.com/event-information.ical Or drop the special scheme and just do http://www.somesite.com/even-information.ical
But there is no way that I am aware of where you can just jump to a certain date in the calendar.