Well the reason why I thought of this is because I have had become lucid many times when I read things. I mean it is a pretty blatant dreamsign! By tattooing that sort of statement on your arm it would allow you to constantly use text observation as a reality check. IF I was to get a tattoo I think this would be it.
@ Graysong: So I am guessing you do not have any tattoos? I would assume that they do eventually become apart of our dreams, but I cant be sure. Hopefully a tatted up LD'er will come answer this question! So what type of variations are you thinking of?