I did this for a creative assignment for my uni course (not related to CG). I was at a loss for ideas until the day before it was due, and so I made this in a single 10 hour sitting. Thanks to Octane, after an hour of rendering, I had something presentable. It was a bit noisy, but no one in my class knows anything about CG, so they didn't notice (actually they thought it was a photo).
I was away from home for a day so it continued to render for 27 hours on PMC.
Volumetric light done in Blender, post-work in GIMP and Paint.NET.
Now that I'm past time constraints, I'm looking to improve/complete the image, so I'm open to suggestions.