At TechFest, Microsoft demonstated several examples of NUI applications. How about screening for colon cancer?
A collaboration between Microsoft, Intel, Vectorform and Massachusetts General Hospital enables much faster and less invasive colonoscopies. This had led to a virtual colonoscopies (using a CT scanner) that now take about 3 minutes instead of 30+ minutes. Previously the process took a lot longer due to the time needed to run algorithms to "clean" the CT images. These images are then reconstructed in to a 3D view of the colon and as you can see in the video, these 3D views can be navigated through using a gesture based interface.
There is a lot of other technology at play here - high performance computing (HPC) platform, Microsoft .Net 4.0, and the Intel Parallel Studio 2011 developer tool as well as a fully parallelized GPU-based volume rendering engine developed by Microsoft Research.