Outlook Calendar Views is a free add-in from Microsoft that fixes a major flaw in the calendar - it allows you to filter you calendar with views the same way you would with mail or tasks. I've been using this add-in since Paschal first mentioned it a month ago and it's very useful. I highly recommend it if you have Office 2003. Also seems to work on the Outlook 12 beta, but it's a bit disappointing we still need an add-in!
Download here. (It seems like this Work Essentials page might be worth browsing too when I have the time).