If you like using your computer before bed, try f.lux. (Yes, it's spelled f.lux)

f.lux: software to make your life better

Lots of my friends in university used it. I personally don't need it since I'm so used to using electronics before bed, but there is psychology behind it.

edit: I think you can get it for your phone as well, but only if your phone is Android. I've heard that iPhones have something equivalent built in, but I don't know what it is, as I don't have an iPhone anymore.