As people geotag more information they need more advanced ways to share it. The way that offers the most control, flexibility and portability is KML, but KML is not easy to work with. (It should be noted that GeoRSS, the other popular geodata format, is an equally portable format, but it is designed to be simple and does not have some of the advanced features of KML. ) You can use sites such as Platial or Google Maps, but they do not let you dig into the KML itself.
Google is trying to bridge that gap with a specially formatted Google Spreadsheet (embedded above with small edits that I made; check it out for yourself; here is the help page; see the sample sheet in Google Maps). The spreadsheet is made up of several sheets. One contains all of the permissions, the network link, compatibility and some error-checking. The second contains all of the placemark data (lat-long of all the points). Others contains the formatting information for each placemark. There is also a sheet that shows a KML view. The video after the jump shows you how to use them all (Google has really been doing a good job with their screencasts of late; it’s a great way to get a lot of information about a complex app very quickly).
Making tools like this more accessible is important for getting geodata onto the web — one of Google’s top priorities. This tool has a ways to go, but is a great first step.