Second-hand frames, spray-painted chocolate brown and arranged as one gigundic "artwork": sounds simple, but this project took a looong time. First, I had to accumulate several frames. I got most of these at a second-hand store, and many of them didn't have hangers, glass, etc. and had to be cobbled a bit. When they didn't have glass, I used an exacto knife on some thick plastic that I had on an old hanging. Then I had to select the photos for each frame and develop them. I arranged them on the floor in a way that I liked, and they ended up in this "football" shape.
Hanging took a bit of time, using a leveller to get the frames as straight as I could. The frames were all different colors and remained that way for some time... Recently, I finally finished the project by taking everything out of the frames, and taking the frames to the backyard for two coats of spray primer, and two coats of paint. This will take all day, and as you have to do short spurts with spray-paint in order not to drip, it will cripple three fingers on each of your hands for approximately three days.
The whole project, with photos, frames, hardware and paint, cost me less than fifty bucks. Still, I recommend that you be not only thrifty, but clinically insane to attempt this many frames. Still, with 23 framed photos, this project could have easily cost me a few hundred bucks. Glad it's done!