In early October 2009, Google released a global update to Google Maps. One of the major enhancements is the addition of parcel data for certain areas. DC is one of them (as well it should be, after all we put our data in the public domain).  The data they are displaying appears to be circa November 2008.  Additionally Google is now acting as a map data provider in many parts of the world, according to industry experts, Google has moved away from using Tele Atlas base data (you’ll no longer see the familiar trademarks at bottom of Google maps).  And most importantly you can now report errors you find on the map directly back to Google – they are really making a full blown attempt at seeing if crowdsourcing works for GIS data!

I should add that parcel data is still not accessible via their API, but given what Google has done recently, it’s only a matter of time…

Below is two screen shots, The first is from DC's property data, the second from the same area in Google Maps.  As you can see some of the parcels appear to be hidden by Google Map park layer. We've sent in a comment, lets see how long it takes to get resolved... Updated 11/24/09, they fixed it! We requested they adjust the parks layer so you could view parcels in this area and they did!! See third image.