Outlook stores your Tasks separately in its own folder which is not connected to your calendar. If you want to plan your day completely then you need to know when you have to do a task.
But Outlook is not able to display your tasks in your calendar.

The Outlook add-in TaskToCal fits this gap of functionality.
It displays your Outlook tasks in your calendar automatically.

Every time you create a new task then a new appoinment will be created in your calendar. The notes and the state of your tasks are shown in the corresponding appointment. If you move your task-appointment in your calendar then the new time will be reflected in your task, too.
Delete a task in your calendar and your task will be erased in the tasks folder.

As your tasks are now real appointments you can print your complete calendar and have the perfect overview.

• See your Outlook tasks in your Outlook calendar
• Plan your Outlook tasks on by hour level - not only on by day level
• Print out your Outlook calendar with you scheduled tasks
• Get Task Reminders on your iPhone.
  There is an interesting post how to synchronize Outlook tasks with iPhone

"TaskToCal" runs on Windows 2000/XP and Windows Vista with Outlook 2000, Outlook 2002 (XP), Outlook 2003 and Outlook 2007.

"TaskToCal" costs only 19.95 USD (includes 1 year free upgrades)