Find the little halogen display lights. These things come in a variety of sizes and wattage. I use the 2-inch models.
Smaller ones are available and make really cool helmet lights.
Grab the wattage you like, I recommend no higher then 20 for any single bulb. These things are almost all 12volt. Rip open the package and take the bulb over to the plumbing section. Once in the plumbing section look around for some PVC pipe in about the right diameter to slip the bulb into so that the ridge on the bulb catches on the edges of the pipe preventing it from sliding in. Also in the section are all sorts of cool end caps and screw on bits that will finish things off.