EveryTrail, the popular GPS track and geotagged photo site, has already announced support for the new tour option in Google Earth 5 (obviously they were beta testers). EveryTrail already has a layer in Google Earth. Now, they offer the ability for folks to upload recorded tours showing off their EveryTrail travel logs.
In their announcement EveryTrail listed several examples. But, my favorite was the one of a hike up Half Dome in Yosemite Park, California. (I made the same hike many years ago). All you need to do is have Google Earth 5 installed, and then load their Half Dome Tour (UPDATE: You must be logged in on EveryTrail to load the KMZ now). Once it loads, double-click on the “half-dome-tour” recorded tour and it will start flying you through the hike and show you photos along the way. Awesome! Users could also add voice narration over the tours if they wanted.