Least carbon-emitting way to charge devices?

[Meshuga]

New here, sorry if this has been discussed.

These are the sort of conundrums that occupy my brain - obviously not enough to do but here goes - mobile phones, PDAs, AA battery chargers, etc. All these devices that we have, is it better to charge them in the car or in the home, in CO2 terms? I've heard it said that when load is place on an alternator it affects fuel economy. Does this still apply to even low power devices like chargers? Also, leading on from this, does it still affect fuel economy if you charge in the car only when the engine is off, i.e., its sat on your driveway. Obviously common sense dictates not to let the battery run down!

Any thoughts?

[Ryland]

it is best to use electricity as it is generated, as you don't get as much out of the battery as you put in the battery, first law of thermodynamics.
so if you must charge your cell phone do it while the car is running, or get a plug splitter and a window mounted solar panel that keeps your battery toped off.
also your charger often uses power while plugged in a wall outlet even if the phone is not pluged in to it, mine is about 1 watt 24 hours per day.