How many times has the birthday of that rich uncle or that six-monthly appointment at the dentist slipped your mind? How many times have you forgotten to put out the rubbish? The solution is either a little mental training — or the idea presented here: an electronic knotted handkerchief.Key features– Space to store from 48 to 94 appointments (depending on the number of distinct events)– Schedule appointments up to 22 months ahead– Set times in steps of one hour– Advance notice period settable from 0 to 255 hours in steps of one hour– Appointments displayed for a period from 0 to 124 hours (without advance notice), settable in units of four hours– Battery life: one to two years using four alkaline AA cells (depending on duration and frequency of displayed appointments)