What to do when you get tired?

So during my long runs, I get tired. Heck during some of my shorter runs, I feel tired. I recently asked most people I know who are runners, what they think about when they start to feel fatigued. Answers ranged from very technical things, like concentrating on form, to things like day dreaming.

When things start to suck, I have 2 things I try, to varying degrees of success. I keep saying "Kate" over and over. I think about telling her I ran a marathon. I think if funny things she does, or when she says "I Love You Daddy." I wish I could say that gets me through everything, but it doesn't.

Other times, I think of songs and start singing them to myself. They range from random ones, to somewhat appropriate ones. Recently I have found myself singing Three Days Grace's "Pain". Especially this part of the song:

"Pain, without love

Pain, I can't get enough
Pain, I like it rough
'Cause I'd rather feel pain than nothing at all"

In hindsight, that seems kind of sick and twisted, but at times it does the trick. It does help remind me that yes, what I am doing is completely stupid, and that pain is natural. The pain is a good reminder that my training is working.

Any advice or thoughts from you other runners out there as to what you do when you start to hate every step would be appreciated.