Users should be able to select which calendars to display separately for appointments and tasks.

Proposed use case: the user has both appointments and tasks in his personal calendar, but some special calendars for projects tasks. He wants to focus on a special project and thus wants to hide all other tasks, but keep all calendar appointments on sight. But deselecting the personal calendar (as task list) would also hide most (and most relevant) appointments.

Possible solutions:

• Completely split task and calendar views (so we have Calendar, Tasks, Address Book, Mail, ...)
• Add a second row of checkboxes to be able to separately select calendars for appointment and task views