I wouldn't normally post about using an application, but nevertheless, this is a very handy trick for me. I usually run Thunderbird and Outlook Web Access (OWA). OWA is good for viewing your calendar, not so much shared calendars. And if I launch Outlook when Thunderbird is already running, Exchange goes crazy with my inbox. So, I often find I want to launch Outlook but only for the calendar. Microsoft has a handy page on how to Customize Outlook to start with the Calendar open. And in summary, you just need to add this to whatever shortcut you use to launch Outlook:
I added this to my quick launch link, the only downside is every time Outlook is updated, that link gets stomped.