We have Exchange 2007 Server running on Windows 2003 R2 Server. We have a handful of mailboxes that we use the calendars for checking out conference rooms, loaner projectors etc. The problem we are having is users are not paying attention when they do a new all day request or appointment and they leave the show as section as free. The other users then dont see the appointment and we get equipment that is double booked. Is there a way to force it (Outlook 2007 and 2010) so when they make the request the only option is Busy. Or is there a better way we should go about setting this up in the first place? Thanks.

I would look at setting the MaximumDurationInMinutes swtich with set-mailboxcalendersettings to something that would make the resource mailbox reject the all day event request. Otherwise, the best option is user education.