I think the article "How to Beat Procrastination" on Less Wrong [1] is quite possibly the best thing written on the subject of procrastination on the web in terms of both writing and research quality. It's based on the temporal motivational theory of procrastination, which is so far the one that best explains the experimental data we've got.
Scroll down the page a bit to see "the procrastination equation". Even though I had been exposed to concepts from the temporal motivational theory before I found the equation quite striking the first time I saw it.
> Motivation = (Expectancy x Value) / (Impulsiveness x Delay)
> Increase the size of a task's reward (including both the pleasantness of doing the task and the value of its after-effects), and your motivation goes up. Increase the perceived odds of getting the reward, and your motivation also goes up.
> The denominator covers the effect of time on our motivation to do a task. The longer the delay before we reap a task's reward, the less motivated we are to do it. And the negative effect of this delay on our motivation is amplified by our level of impulsiveness. For highly impulsive people, delays do even greater damage to their motivation.
The rest of the article is worth reading. (It's short; 2/3 of the page is footnotes and comments.) Firstly for the examples that root the equation in reality. Secondly for suggestions on increasing the numerator and decreasing the denominator.
Scroll down the page a bit to see "the procrastination equation". Even though I had been exposed to concepts from the temporal motivational theory before I found the equation quite striking the first time I saw it.
[1] http://lesswrong.com/lw/3w3/how_to_beat_procrastination/