Prompting personal warning before putting my Macbook Pro to sleep I carry my Macbook Pro (15" Retina, Mid 2012 with Mt. Lion) between my work and home. It is connected to an external HDD as a Time Machine. I always forget to properly eject the HDD before putting my notebook to sleep (I rarely shut it down) at my office.

Is there a way to have it prompt with a custom reminder or warning when I try to put MBP to sleep, using Automator or something?
You could have the drive automatically ejected when you sleep the mac instead?

Quick search found Jettison on the Mac App Store
http://itunes.apple.com/us/app/jettison/id447430809?mt=12

There is also an app you can use to run Apple script on sleep/wake:
http://www.lagentesoft.com/scenario/index.html