A great video on running form / technique:



I first saw this video posted by the Learn to Run initiative: http://www.facebook.com/learntorun

* Update 1.20.2011 *

For me, "neutral hips" is not a sufficient cue... I have always tended to slouch so "neutral" to me would be too far back, even if I pulled my upper body into an upright position. I have to lift my hips up and push them forward (which by the way uses a whole bunch of new muscles if you have been a sloucher for 25 years) in order to get them into the proper position.

My visualization technique for folks who might be sitting back too far behind your center of gravity:

** Lift your hips as if you need to place your private parts up onto a table or counter. **

Then I proceed to straighten the upper torso, bend the knees, and lean at the ankles. This allows me to "fall forward" and run with far less effort.