Let's face it. This is the time of year where it isn't always practical, feasible, or safe to run outside all the time. Make friends with the treadmill, or at least try to be friends with the treadmill. I promise running on a treadmill is better than no run.
I've gone as long as 14 miles on a treadmill. While it wasn't easy, it wasn't unbearable either. I think I learned more from running 14 miles on a treadmill than running 20 miles outside.
Random tips for keeping yourself on the "hamster wheel" (or dreadmill, but I prefer hamster wheel):
1. Set the incline to at least 1%. The forward motion of the belt actually mimics running downhill.
2. If you are switching from running outside, don't switch too abruptly. Like anything in running, you don't want to make sudden changes.
3. Expect it to be different. Some people find it easier while others find it harder to run on a treadmill.
4. Find ways to entertain yourself. Program your mp3 player with your favorite tunes, watch a movie or TV, and make up games.
5. Practice your mental skills. It is not always easy to keep yourself motivated to stay on the treadmill.
6. Vary the inclines and speeds. It'll help to keep you from getting bored. Plus intervals are good for you.
7. Put something over the time/distance display, especially if you are tempted to constantly look at it.
8. It is possible to do long runs on the treadmill. Break it up into smaller pieces, say 5-7 miles. Plan breaks to fill up your water bottle, go to the bathroom, and get some fuel.