Local Google Calender

Although I haven't tried it by myself yet, this seems useful. It is still its early stage, so it has several restrictions, but we can hope for its future.

Edit (4/16):
I tried by myself and it turned out that it was not so useful because the Google Calendar provider doesn't cache the entries. If you cannot use it offline, what's the point of using Google Calendar from a standalone application? We'll hope for the future.