This notification would involve your screen saver. It would pop up with a picture of the person, and either a message that reminds you of the friend, or a specific instruction as to what you should do with this friend / significant other / family member. The picture itself would be stored locally and updated occasionally using the internet. There is also the possibility that all the information would be on the internet. However, the reminders would be saved locally so with or without the image you would get a reminder.