Exchange 2003 Resource Booking
One of the benefits of having a calendaring application is to use
it for resource booking such as conference rooms, special equipment
or actually anything that needs to be shared.
The following article by Markus Klein, published at www.msexchange.org is
a very good guide to configuring such resources and working with them:
http://www.msexchange.org/tutorials/Booking-Resources-ExchangeServer-2003-Outlook-System-2003.html