For me the best way is to run with others. This year I've been struggling with the boredom factor too as my best running buddy is injured and not running now. Normally I make her run all or part of my long runs with me. I have another newer running friend and we are able to run together sometimes but our schedules often don't mesh. Last week I went out and ran 4+ hours by myself. Being alone was the hardest part (and I was really alone out on an island in the Great Salt Lake; I think I saw 3 people total in the 4 hours). The running part was surprisingly easy (well, as easy as running for 4 hours can be).

Finding a good partner is hard. I have many running friends that I don't actually run with because they are just too fast. So I usually wear the iPod when I am out on long runs on the trail (I don't run on the road). Most of the time I can work myself into a Zen-like trance and literally just think about one foot in front of the other. Other times I occupy myself with my eating and drinking schedules. And then other times I think of it as a series of small runs, focusing on making it to point x, after which I will worry about making it to point y. I talk to myself a lot (I don't sing because it tends to interfere with my breathing ). Sometimes in the winter when the trail conditions are really tough I fight breaking into tears because I am really wishing I had a partner in misery

So I guess I'm all over the freaking place mentally. Maybe that's how I manage!