I find it incredibly annoying that laptop lights blink when they're on standby - I often put my laptop on standby when I sleep and then I have a light either blinking or "waxing/waning" in my face (I like to sleep in complete darkness). My improvised solution is to throw an item of clothing over the laptop now.
One could also add a few blinking states. Slow blink = charge, fast blink = problem, two quick blinks = alert, etc.