One of the few things I saw at the ADA meeting in New Orleans that was truly new and unique was LocalMed an online service that allows patients to actually book an appointment in your office.
I believe we are ready to take that step. Of course you do not allow patients to take control of the appointment book but you can make limited appointment times available. For example you could allow new patients to schedule an exam or existing patients to schedule or change a routine prophy.
LocalMed is still quite new, it does not yet integrate with all the major practice management systems and is expanding both as a service to dentists and to patients seeking a dentist.
I really like the concept and properly set up and managed I believe it would be a great asset for any practice. I predict two things will hold it back in the beginning. Dental practice management systems that do not allow outside parties to work within the software and dental office administrators who see it as a threat.