I'm on a mission to decorate and furnish my new home on as little as possible (why spend big bucks when you can craft it yourself for much less?) and these photo ledges definitely fit the bill!
I modified mine to be only 48" long (instead of the full 8') and used a 2x1 instead of a 4x1 for the bottom board. All together, my wood was about $4.50, and I used a can and a half of spraypaint for the finish. It's directly screwed into studs in the wall, so these things are very solid. Now I just need to figure out exactly what photos I want to display!