Subway Path Finder Subway Path Finder is a Flash based route finder for a number of subway systems around the world. Currently the application works for LA, New York, London, Paris, Berlin, Barcelona, Madrid, Moscow, Tokyo and Mexico City. To start using the application you first need to select which city's subway system you want to use. Once you have selected a city a map of its subway system will load. You can now select any of the subways stations as your starting point and destination by simply clicking on any of the stations displayed on the map. Once you have selected the route an animation will play showing your route and any changes you need to make on the journey. Two Google Maps are also displayed to show your starting station and destination station on a street map. The application also comes with the option of getting a route from any location to museums, restaurants, theatres, nightclubs and hospitals. When you choose to view a route to any of these points of interest the Google Map also shows you your walking directions from the nearest subway station to your choice of museum, hotel etc.

I get a few emails every day regarding Google Earth's "historical imagery" feature, so now seems like a good time to revisit the topic. Frank first wrote about this new feature back in early 2009 when it was released as part of Google Earth 5. I'll leave his content below, as it's a great introduction to how it works, but first we need to discuss one oft-overlooked aspect of historical imagery.

Historical Imagery can be newer

We mentioned it back in February of this year, but it's important to realize that the newest imagery in Google Earth can often be found in this historical imagery feature.

Google is very careful about the imagery that they release to the default layer. If new imagery is good (but not good enough), they'll often it put it in the historical imagery layer. Reasons why it might not be "good enough" can be due to some clouds in the way, haze/pollution, sun at the wrong angle (lots of shadows), and things of that nature. Despite whatever minor shortcoming it may have, the imagery still may be of value to you, so be sure to check for it.

How to use the Historical Imagery feature

Google already had more satellite and aerial imagery available for free than anyone. Now, they've added a new feature to new Google Earth 5 that let's you turn back the clock and see other imagery they have for locations around the world. Click on the little "Clock" icon in the upper middle (or the "View->Historical Imagery" menu item). A time slider appears (see below) showing available imagery. If other imagery is available in your current view, you see little tic marks on the slider. Drag the slider (or click the left/right buttons) to see earlier or (or even newer) imagery.

For example, here's a shot of the famous "Bird's Nest" stadium from the 2008 Beijing Olympics as it appeared under construction on February 17, 2007:

This feature is amazing! The amount of data Google is storing must be immense! Several instances of imagery for millions of square kilometers! You may be able to see how your house changed over the years, or see aerial pictures of cities from decades ago. Expect to see lots of posts on this new feature.