A launch from Google that's sure to go down well: MyMaps, rolled out in the last few hours, lets you create your own personalized maps within Google Maps.
You can mark your favorite places, draw shapes to represent areas and lines to represent journeys, publish your map publicly and share it with friends. Playing around with it a few moments ago, I noticed a very cool feature: support for rich media like videos from YouTube and Google Video.
But in another sense, it's a shame that Google would launch such a product: startups like Platial and Frappr, not to mention thousands of smaller sites, have built businesses around social maps (provided by Google Maps, Yahoo Maps or both). By providing its own service, Google has instantly killed off at least a few hundred of those mashed-up tools.