Photosynth is currently supported as an addon for Mozilla Firefox and Internet explorer.Another requirement is a good graphic subsystem installed for all the graphic shine. So if you have an older graphic card on your pc like the Intel’s 8xx series then Photosynth will not work.The application is free to boot and has an inbuilt image gallery to view some cool stuff.

Here is a screenshot of Photosynth in action:

Here are some notable features of Photosynth :

• Occupies less memory – You must have an active Xcontrol in the system (about 5mb) for Photosynth to run. It doesn’t occupy large disk space.

• Awesome Zooming capacity - Perhaps the best feature of the Photosynth, whether the image is megapixels or gigapixels in size you can zoom in and out without any hesitation whatsoever.

• Navigate in 3D model – Photosynth provides easy controls for exploring large collection of photos in 3D with a simple click of the mouse button.

• Web application - Photosynth can help you connect your photos to the tubes we call the Internet, allowing you to browse a virtual universe of interconnected scenes that constantly evolves and changes over time.

Microsoft Live Labs says their are plenty of other features as well which are to be explored, but i suggest you try out Photosynth Now!