With Exchange 2003, you couldn't open another user's mailbox from OWA. With Exchange 2007, you could -- but it opened in a new IE window and you couldn't select the mailbox from the Global Address List (GAL). With Exchange 2010, you can select a mailbox to open from the GAL, and it "nests" into the left pane along with your default mailbox. OWA also remembers which mailboxes you opened and displays them when you log on the next time.
Another feature that's been on the OWA wish list of many Outlook users is the ability to open up a shared calendar and view it side by side with your own calendar. This is invaluable if you need to make plans that include coordinating your schedule with someone else's. You can share your calendar with other users of your Exchange 2010 server.
1. Right-Click People's Calendars.
2. Select Open a Shared Calendar.
1. Click on Name to open the GAL (Global Address List)
1. Enter the name in the search field.
2. Double-click on the name you want.
3. Ensure the name now appears in the Name: field.
4. Click OK.
The calendar is now visible.