Your phone is your 3D scanner
Or it can be, with the amazing ProtoFly project. In short it allows you to take a few pictures of an object and using their Windows-only software pictures are uploaded to Autodesk servers and a 3D model of your scene is obtained.
Either small objects, the interior of a room or the outside of a building can be "scanned" just with a cellphone camera. And don't underestimate the power of this technique (photogrammetry). I have been more than impressed with the quality of the output mesh. And given that the service is free of charge I cannot complain about the price :-)
Once you've got the 3D model of your scene the next problem is how can you start editing it and showing it to others. I have found a very nice piece of software called MeshLab that does a great job and it is a multi-platform open-source solution.
But the coolest thing is that there are some cellphone apps that can show a 3D object too. I am still fighting with one of them called "Shader Devel and 3D Viewer" that might do the job once I figure it out.
The video below shows the first capture I have attempted using just 2 Megapixel images. Please note it is not a video but a 1080 rendering of the textured 3D-model (scene has not been properly cleaned up so some objects are levitating into the air).