Clearly I go to bed too early. Late last night, Google Maps added a new feature called “My Maps,” which seems to be Google’s response to the collections feature in Microsoft’s Virtual Earth/Windows Live Local/Live Maps. In a nutshell, it’s a dead-easy way to create maps using an in-map click-and-drag interface: pushpins (with HTML in the info boxes), lines and areas are all possible. Maps can be saved, shared, and, because the data format is KML, viewed in Google Earth.
Blog coverage: Google Maps Mania; Mapperz; Free GeoTools; Hablandodesigs. Frank’s got a detailed rundown on Google Earth Blog; Stefan compares it to Microsoft’s collections and to a third-party map-builder based on Google Maps, Tagzania.
The bottom line seems to be that you can do a lot more with the Google Maps API directly, or with something like Tagzania, than you can with this new thing, but that this is a very simple way of building simple maps atop the Google Maps engine.
Update, 10:30 AM: Google’s announcement.
Update, 8:10 PM: User guide.