I was looking for the same functionality, this is standard behaviour in many calendars (e.g. Outlook 2007).
It is the easiest way to create a long appointment, just drag a rangen of hours and then click or enter to fill in the details.
Would it be difficult to create this client-side? (There is only a clienttimeslotclick event, but not clienttimeslot-dragstart/dragend events)
Thanks in advance...