Spirit of Indiana
Do you remember the travel/flight sequences in the Indiana Jones movies?
Hacks.mozilla.org remember them so fondly that they decided to recreate the effect with Google Maps and a YouTube video. The result is pretty awesome as you can see in the video above or see for yourself on the demo page.
Now you've seen it I bet you want to recreate it yourself. Luckily help.mozila.org have also written up a full tutorial on how they created the application.