This is a really fun form of photography. It’s called Through the Viewfinder and it’s a simple concept: use one camera to photograph a subject through a vintage camera’s viewfinder. I just got this little 1939 Ensign Ful-Vue off of ebay for the task.
For more about my first TtV photography, the restoration of a vintage camera, and the process I went through, please have a gander at my Through My Viewfinders set on flickr. Expect to see a lot more of this stuff from me. If you’d like to see what others are already doing with TtV, check out this group on flickr.