[Piwoslaw]

When I carpool with someone I set the rendezvous point in a place that minimizes driving/fuel usage. For example, when I hitch a ride with my neighbor, I go over and wait in his driveway so that he doesn't have to wait for me with his engine idling. I might even help close his garage door and gate to speed things up. If someone is picking me up/dropping off then I meet him at the main road, so he doesn't have to drive up and then back down my street.

This may be splitting hairs, but I charge my GPS at home (via USB) so that it reduces the alternator's load by that much. If the trip is longer and I need to plug in, then I unplug it 30-60 min before turning it off so that it discharges again. Of course, I don't use it at all in places I am familiar with. Though I often see people driving the same route every single day with their GPS on.