What do you do when you can't sleep?

[realistic]

For whatever reason I am blessed with the curse of not being able to go to sleep easily 4 out of 7 nights during the average week. I literally get less than 4 hours of sleep on these days because I just can't doze off. Sleep medications don't even work. I occupy my time messing on my website(s), brainstorming and playing on forums. (Like right now!)

What do you do to pass the time when you can't sleep!