I found openSCAD a little while ago and started to play around with it. At first it seemed rather rudimentary when compared to SolidWorks, AutoCAD and others but it really grew on me. The power of scripted cad really becomes apparent after using it for awhile: with enough forethought you can design scripts that are able to be easily modified to fit other applications, allowing universal designs. To that end I designed a lens mount that should be universal to almost any camera lens.
I’ve also designed a number of other simple tools: