I've considered cyanide too, but it sounded like it might be quite agonising (lostallhope website). There was a story I read, apparently true that a guy ate a coffee cup full of apple seeds to prove to another guy that they didn't contain cyanide and well, he didn't last too much longer after that. I wouldn't necessarily recommend you follow his example. I think cyanide can be quick but I don't think it's at all pleasant to say the least! :-0