Microsoft is unveiling its latest 3D version of Photosynth today. Launched as a preview to accompany the new Bing Maps app, Microsoft is updating its Photosynth imaging stitching technology to include four new modes: spin, panorama, walk, and wall. The new modes will be available exclusively to those who join the preview program, and Microsoft is accepting sign ups on a first come first serve basis. A new spin mode allows images to be uploaded to the site and compiled with Photosynth to produce an embeddable photo that is 3D and similar to Seene for iPhone.