I've set up a SBS 2008 Server for our small business (medical practice with
four partner physicians). I'm creating a common calendar for partners' work
schedules, using categories such as "on call," "vacation," "business
meeting", etc.

I'd like the subscribers to the calendar to be able to submit requests for
time off, on-call changes, etc., to our office manager so that she needs to
massage the requests as little as possible before posting them to the shared
calendar.

Can anyone suggest a streamlined workflow for this?

Most subscribers will have Office Outlook 2007 as their client. A few will
be using Outlook Web Access.

Thanks so much,
Jim Robertson