So you've used Google's cool My Maps feature and laid out your map.  What if you want to then export the data to KML or GeoRSS format for editing?  As of now, there's no easy one click way to do it.  But alas, it can be done and its really easy Open up your map.  Across the top right of your map you will see a few options; View in Google Earth, Print, Send, and Link to this page.