This looks great, and I'm sure I'll find a use for it.
Is it possible to have a certain amount of time blocked out after an appointment is made, so if I am travelling to appointments, leave a 30 minute gap where nobody can book another appointment.
Also, using the system you've set up here, would it be possible to add the ability to make half day, full day and weekly bookings, though that may be another plugin. This would allow for bookings of B&Bs, holiday homes, hotels, etc.
Thanks and great work :0)