Create an EZ button to respond to an email with my Outlook calendar availability. Optional parameters could be start/end dates, single day selection, from (earliest) time, to (latest) time, show tentative as available, etc.
I don't know how many emails I respond to from people outside my organization asking for "best times to meet over the next 3 days", for instance. Being able to generate and insert my availability from my Outlook calendar in a reply would be wonderful.