I usually bring my handheld GPS with me when travelling. It's an older Garmin eTrex Legend that does mapping, but does not do routing. I've used it a lot for Geocaching and it's been great for that. I logged our main driving trips while on vacation in Costa Rica and today I spent some time playing around with the logs in Google Earth and Google Maps. I've used Earth and GPS logs quite a bit in the past, but the new Maps allows me to create a custom map and to import Google Earth kml files - so I can create and embed Maps links with my GPS info on them, viewable from any browser without the need to install Google Earth. Here's the map of our driving in CR. I'm going to experiment with adding some photos to this map.
View Larger Map
The other cool thing you can do if you have Google Earth is to download the kml file for this route and replay it in Tour Mode. It will follow the specified route, giving a birds-eye view of the drive. Chose the View Larger Map link, the the View in Google Earth link on that page to load the kml into Google Earth on your computer.