I’m planning a round the world tour and have been looking into options for geotagging photos and posting our path online. After a bit of research I think a good option is to go with the geotagging feature of Picasa. It is a fairly straightforward process which involves selecting the photos in Picasa, zooming round the globe in google earth and clicking on where they were taken. I considered carrying a gps (Leo Laporte on the “mac break weekly” podcast was big-upping Garmin Nuvis recently) on me at all times and recording tracks but the battery life of the gps was going to seriously limit how much I could record. We’re looking at a max of 8 hours of tracking — that is no use in the Amazon basin where there are no plugs.
For fun I might build tracks on google earth and post them too. I can use my gps to locate points of interest (will need to pay $20 for GE plus if I want to use GPS directly with it) or just zoom round. To prepare for offline access I’ve upped my disk cache in GE preferences and will cache images before we head out. You can do this by setting a collection of way points and then playing a movie that flies over them. As GE goes along our trail the images will get cached and I can replay them in an offline state [details].