The Windows Live Calendar service was recently updated to include a new feature: Group Calendars. If you’ve already created IM groups within Windows Live Messenger for instant messaging with a select group of your IM contacts and friends, you’ll now see that group has its own calendar within Windows Live Calendar. The group calendars are automatically created for you and are displayed along with your personal calendar as an overlay within the service. You can either visit calendar.live.com to access this feature or you can right-click on the group in WLM and click on “Calendar” to be taken to the group calendar page.
Anything you add to the Group Calendar will show up on the calendars of all the other members of the group, too. Although the calendar is automatically shared between group members, sharing with others is only possible if you invite them to join your group.
The Group Calendar feature is a great example of the integration we’re seeing between the different tools available in Windows Live, all of which can be downloaded from here.