Just stumbled across another Excel .XLS file with macros that will convert a list of coordinates and descriptions into a Google Earth KML file. Not particularly fancy, but easy to use and works well.
excel2kml uses VBA, so you’ll have to have Excel (i.e. it won’t work with OpenOffice). Open the file in Excel, and enable macros if they’re disabled for security purposes. First page is the data sheet, with a set of sample data already in place: Name, Latitude, Longitude, and Description are the only data fields available. Paste your data into the data sheet (up to 50,000 lines), enter Alt-F8, and run the “Generate KML” macro. A file called “myfile.kml” will be created in the root directory of the C-drive; you can modify the file name and destination in the “File Details” tab. That’s it – tested it with the sample data and a file of my own, and works perfectly. You could probably modify it quite easily to meet any additional requirements you might have.