View another user's calendar in Outlook Web Access (Exchange 2007 OWA)

From ben.goodacre.name/tech

Use the following format URL:

https://<OutlookWebAccessURL>/owa/<PrimarySMTPAddressOfTheOtherMailbox>/?cmd=contents&module=calendar

Where:

<OutlookWebAccessURL> = the URL you use to access Outlook Web Access normally

<PrimarySMTPAddressOfTheOtherMailbox> = The primary smtp address of the mailbox. This is also referred to as the reply address.