Well, this project in and of itself was pretty much an exercise in failure, but I figured I'd share anyway. My goal was to create a low-draw, portable reading/courtesy light that plugged into 12vdc outlets I've been scattering throughout the boat for fans and such. Long story short, a parallel project (creating a light string for a craft project of my GF's) led me to realize standard Christmas lights will run off 12v when placed in 5-light series strings. Anyway, on to the project:
First, I cut a short piece of 1 1/4", schedule 40 PVC tube. This was formed into a flat sheet (drop it into boiling water and you can form/cut PVC like thick rubber), and cut with a hole saw to fit flush to the end of the remainder of the tube. Drill 5 holes to fit the Christmas lights, and wire in series (soldered Western Union joints)

Next, I cut the tube to the length I desired, and drilled four holes (opposing sides, top and bottom) for the support wires. The wires were fished through as shown below. These were just 12" strands of 12 ga Romex solid core wire. They were attached similarly to the male plug later on.

With the support wires in place, I glued the top disc with the lights in it onto the body of the lamp. The wires for the lights were threaded through a central hole on the bottom disc, while the support wires each exited their own seperate holes on opposing sides of the lamp body. This was then cemented on.
Next, the two electrical wires were twisted together, then braided with the two support wires. Attach to the male plug and in a similar fashion, and you have a reading lamp!

For some reason, I never checked whether or not the Christmas lights actually put out a decent amount of light in the forward direction. They don't. But I got 250 of them for $1, and a group of 5 only draws 0.1A, so I thought I'd give it a go. The next one will be LED of course, but I'm currently doing a study of the various lighting aboard, and determining exactly what I need.