1. Get a Running Buddy
2. Play Beat the ClockI love doing this when I'm running an out-and-back route. Begin timing your run as soon as you start. At your turnaround point, hit the split button on your running watch/timer, or just take note of your time. Try increasing your pace on the way back, with the goal of beating your time for the first half (which, by the way, is called a negative split).
3. Do Some Hill Repeats
4. Do a Random Interval WorkoutPick a landmark in the distance, such as a tree or a stop sign, and pick up the pace until you get to it. After you recover for a minute or two, choose another landmark and speed up again.
Also see: Tips for Being a Friendly Runner
6. Count 'Em UpIf you run where there are a lot of other runners, try this game: Pick out a specific article of clothing, such as black running shorts, to look for during your run. Then count how many runners you see wearing that piece of clothing. If you're running with a friend, you can each guess how many you'll spot during the run and then see who comes the closest.
Also see: 10 Things Runners Should Stop Doing