I’ve been waiting for this. You can now supply a KML to Google Maps that contains a network link based on a view boundbox and it will work similar to how it does in Google Earth – with no editing needed!
They supply the examples of Panaramio, Placeopedia, Wikimapia and some others. I’ve whipped up some for Google Earth Hacks — our GEboards (view-only) network link, our full list of files (focused on the center of your view), our newest submitted files and our most popular files. Here’s another one I did that shows 100 golf courses nearest your center of view (United States only), courtesy of GolfNation.
These are amazingly easy to create, because they all use the exact name NetworkLink that is used in Google Earth. Very slick!