Make3D is a project from two Stanford students that won a 'best paper' award at the International Conference on Computer Vision in Rio de Janeiro in October 2007.
The online service takes a 2D image and creates a 3D'esque fly around models that include depth and a range views. Photos can be uploaded directly or pulled into the site from Flickr - however the service requires that you rate at least five images before you can pull them in from Flickr. You can jump in and just use the upload from hard drive option though
Click through to this link to see an example of it in action from a photo I took in Egypt at the pyramids:
Note: it doesn't work for Intel Mac and Shockwave but there is a workaround for installing a VRML viewer for Linux which will be given to you as an option.
The tech lowdown on the algorithm from January Stanford News Service :
…the algorithm breaks the image up into tiny planes called “superpixels,” which are within the image and have very uniform color, brightness and other attributes. By looking at a superpixel in concert with its neighbors, analyzing changes such as gradations of texture, the algorithm makes a judgment about how far it is from the viewer and what its orientation in space is. Unlike some previous algorithms, the Stanford one can account for planes at any angle, not just horizontal or vertical. This allows it to create models for scenes that have planes at many orientations, such as the curved branches of trees or the slopes of mountains.
An excellent diagram on the process can be found here.
This is one of the first web services of this ilk out of the starting gate. Microsoft have had Photosynth for a while but instead of using one image to derive the model it meshes together multiple images.