Apple has announced a beta version of a completely revised MobileMe Calendar. The new service adopts the look and feel of the iPad's Calendar app, in keeping with the trend Apple started when the company revised MobileMe Mail recently. But the changes aren't merely cosmetic; Calendar now uses the open CalDAV standard rather than a proprietary method of transferring data. One result of this change is that MobileMe users will be able to (finally!) share editable calendars with other users, a feature that previously required third-party software such as BusySync or BusyCal. In addition, users can now create read-only group calendars (much like one could do in the erstwhile .Mac Groups) and can track RSVPs for event invitations.

All this is fantastic, and if I may say so, long overdue. Of course, it also means I'll have to completely revise my Calendar coverage in Take Control of MobileMe, so the update I've been working on will take a bit longer than I previously thought.

To participate in the beta program (no word yet on when the service will officially roll out for all users), log in to your account at http://www.me.com/calendar and click the Request an Invitation link in the lower left corner. Then wait; Apple may take days or weeks to process your invitation. (I requested mine within 12 hours of the announcement, and I haven't received my invitation yet, although Dan Frakes, who edits the book, has received his.)

But beware: during the beta period, some features are missing and others are incomplete, so switching to the new calendar in its current state may cause some problems while causing others. Read all about the service's features and requirements in Apple's FAQ, and also be sure to read the known issues page.

—Posted by Joe Kissell on July 11, 2010