Catalin Niculescu shares his latest plugin for Maya N_Loc which allows you to create any shape as a custom locator in Autodesk Maya.
“N_loc is a maya locator that does not use predefined shapes. Instead, using the provided nLoc.py, you can create any shape using either your own presets, or simply objects (curves and/or meshes) in your scene. You can create an n_loc out of any number of curves and/or meshes. As far as meshes goes though, keep in mind that only quads and triangles are supported, nGons will be skipped.”