No SMS reminders as I have a smartphone, which brings me to THE essential feature: the ability to sync with a phone. By sync I mean that it should either have a standalone application or use a built in application on the phone (Exchange), being accessible via the phone browser does not count.
Most people have a phone on them all the time, making it the perfect device to keep a calendar.
Most people have a phone on them all the time, making it the perfect device to keep a calendar.