The process of converting them is pretty straight forward after you get your track log downloaded to an IGC file. Lots of ways you can do that. One of the easiest ways is to get GPSDump, a free program.
Once you have your IGC go to the GPSVisualizer site. Here you can convert the file to a Google Earth KML or KMZ file. You'll have plenty of options to choose from but generally all you need to do is the following:
1. Choose Absolute for the Altitude mode in the Track Options section.
2. I use colorize by Altitude / Elevation.
3. Choose Yes to add time stamps.
4. Upload your file (IGC) in the Upload your files section
5. Click create KML
The files will be available for download in a minute and should open in Google Earth if you have it installed. The latest version will allow you to use the time bar near the top. This new tool with the latest version allows the user to scroll through the flight.
Here's the Google Earth file after it was created
