Land Lines will match any squiggle you draw to a real place on the planet.
The planet is a gloriously varied place, where almost every pattern you can think of can be spotted from the sky—even, say, the letters of the alphabet. Google's latest Chrome experiment, Land Lines, proves that any shape you draw already exists somewhere else on the planet, whether in the contour of the highway, the curlicue of some cape, or in the line of the waves beating the shore.
As explained in a post yesterday on the Google Earth blog, the Land Lines app presents you with two options: Draw and Drag. Click Draw, and you can draw any line you want, and Google will match it to an identical contour somewhere on the planet, as seen from Google Earth's satellite view. These lines can only be a couple inches in length, though. The more magical experience is the Drag function, which matches a long, continuous line you draw with a dynamic patchwork of map tiles, each one containing a section of the line you're drawing. These tiles might be from Mauritania, or they might be from Minneapolis, but when pieced together, they all become an "infinite line of connected rivers, highways, and coastlines," as put by the site page.
It's a fun project, but also a technically impressive one: The Land Lines web app is lightning quick on both mobile and desktop, despite the fact it's crunching data to detect lines on satellite images of the entire planet. This sort of speediness would normally require beefy backend servers to do all the edge-detection, but according to Google, advances in machine learning and GPU power allows almost all of the app to run locally within people's browsers.