I've pretty much ended up with a bruised nose because I've fallen asleep whilst either reading an ebook, or just surfing forums. Hurts like hell when it happens too lol
Reading through the difference experiences has been fun.
One thing that helped me with the iPad, is the iPhone. I used to read it at a distance and having fallen asleep it would bang me on the head.
So when I started with the iPad, I was more careful. However, I still fell asleep and suffered the consequences. Luckily, it was closer to my face so it didn't hurt as much.
But just last night I was reading in bed on my back and fell asleep. I woke up to feel my arms falling -- and the iPad. Luckily it landed on my chest area and missed my face. Definitely won't do that again ... well until I forget.