I will be outlining the build of a DIY headlamp that does require any special tools (except for a soldering iron). It runs off 3x AA NiMH cells and has 5 modes - Hi > Mid > Lo > Strobe > SOS. Here is a beamshot (at 1M on medium) as well as current draw and runtimes based on 2200mAH cells. Total cost parts, excluding batteries, should be under $15. The next post will describe the parts required for the build - and where to get them.