Fliqlo Screensaver - A screensaver that displays the time using a flip clock.
Simply Remind Me - Free email and text reminder service so you don't forget the important things in life!
Padbury Clock Screensaver - Minimal screensaver for Mac
FollowUpThen - The simplest way to schedule an email reminder
Really Slick Screensavers - Really Slick contains free 3D OpenGL screensavers.
Kana Reminder - Kana Reminder is a program which can be used to set a reminder to be triggered at a specified time.