I agree with the others - some variation would help.
When I was still seriously involved in distance running, one recommended training regime was something like:
Monday, Wednesday and Friday: Distance running.
Weekend: Sprint work in the style behemoth79 mentioned earlier.
Tuesdays, Thursdays: Stretching, arm and abdomen exercises.
Also you didn't mention your distance or type of terrain you were covering with your runs. The ideal terrain would be a mixture of hills and straights. If you are unsure of the distance you are currently covering, I'd suggest investing in a pedometer. They can keep track of how much you are actually running, and you can gradually increase both your distance and your speed.
Speaking of which, I ought to drag my lazy ass off the computer and towards my running shoes.
-Ramjet