Life Duration and Rebirth Did Buddha speak about the duration of lives in any way that related it to where one currently stands on the path?  For example:  "When one is closer to enlightenment, one will have shorter lives after each successive rebirth."

This wouldn't make a lot of sense when following the literal doctrine of Rebirth, but maybe it would make sense as a metaphor.

At any rate - is anything like this idea touched upon in the sutras?
Life expectancy (Ayu-Kalpa) changes, but not related to any individual's progress. This is related to the whole society itself. 


  Ayu-Kalpa - a variable time span representing the life expectancy of a typical human being in a particular era or yuga. This can be as high as one Asankya or as small as 10 years. This number is directly proportional to the level of virtue of people in that era. Currently this value hovers around 100 years and is continually decreasing.


Source: http://www.wisdomlib.org/definition/kalpa

As society declines or improves life expectancy declines and improves. A rough outline is as follows:


stealing 1st &amp; 2nd thieves given financial aid - 80,000 years
killing: 3rd thief executed; stealing grows - 80,000 years
beauty decline; killing is widespread - 40,000 years
lying: beauty declined further - 40,000 years
slander: some beautiful, some ugly - 20,000 years
sexual misconduct: the ugly coveted the beautiful - 10,000 years
harsh speech &amp; idle chatter - 5000 years
covetousness &amp; ill will - 2500 years (some 2000)
wrong view - 1000 years (some 500)
abnormal lust, excessive desire, deviant conduct - 500 years
disrespect towards all elders and the holy life - 250 years (some 200)
beauty declines further - 100 years
life-span at its shortest; widespread immorality &amp; war - 10 years


Adopted from: Commentary on Cakka,vatti Siha,nāda Sutta