I play guitar, and have a modest set of effects pedals. These pedals tend to get strewn about (my kids love to reconfigure them), and their wires (signal and power) are a mess. I need a pedalboard to organize the pedals.

I could buy a commercial pedalboard, but it seemed like an interesting project that could be made cheaply. It's actually equal parts woodworking and electrical.
I built the base out of 1/2" plywood and beveled the bottom at 10° so the front edge would be flush with the floor. I then painted it black and attached some Velcro.
I got a 9VDC switching power supply, velcroed it tt the underside of the board, and voila! - instant pedalboard.

Here's the power supply tucked underneath: