Ooh, I forgot all about that one! Missed it, too.
I remember staring at that ad when I was a kid wishing I had one.
Had the watch been a big enough success, maybe there could've been a digital watch based on Trek II director Nick Meyer's The Day After! Just imagine, a digital watch which shows how many seconds you have until you get flash-vaporized!
I had one of those. Unfortunately I took the back off one day to look inside at the circuitry and lost a spring that stopped the sound working (sound = beeps) :(