On April 1, Google introduced Street View in 3D. The technology used is anaglyphic, meaning that your typical cyan/green 3D glasses can be worn for the effect when using this. Sets of glasses can be found with 3D movies, like
Coraline, and used to view the world online from a new perspective. Although the change in the picture is not particularly drastic, it does add an extra sense of depth when using Street View for travel purposes and other reasons as such.
To use it, open up Street View, select your desired location, and click on the icon in the bottom left corner. Doing so will enable you to view the scenery in the third dimension.
Street View with 3D disabled
Street View with 3D enabled