You could set them up on your bedside cabinet (I seem to remember a little wire stand pops out from the back of some of them to prop them up), batteries lasted forever so would have made a good alarm clock for kids. I don't think I ever used to wake up to an alarm as a kid though, but handy to check the time.
I have a strong memory of my dad becoming a bit addicted to my Donkey Kong dual screen when I was about 12, one day I left for school and he was sitting up in bed playing it, and when I got home he was still playing and shouted at me to not disturb him as he was getting a high score... haha.