The AIDS.gov blog has four excellent posts on SMS Text Messaging for appointment reminders, medication reminders, and treatment compliance.  These posts are very timely and the information provided is applicable to virtually all healthcare providers.

Several vendors mentioned in links below offer solutions that schedule and track appointment and medication reminders.  Our SaaS solution,  InphoniteVoice, offers the ability to send SMS text messages for as little as $.10 per message.

Part I - Why

Part II - How    

Part III - Costs

Part IV - Privacy