Local Tools 1.0.0 (maya script)
rotate around edges, move along them, etc...
rotate around edges, move along them, etc...
Update (23.1.07). Supports Maya 8.5. Added menu items for Maya versions 8.0, 8.5.
This tool was designed to allow transformation of
objects/components in various local axes. You first select the
components/objects you would like to transform. Then you invoke the Local
Tools and pick the component/object reference for the orientation you
want to work in. Orientation reference can be an edge, vertex, face (including the
normals), 2 points, other object space and more. After that you are
free to perform any kind of transformation with Move/Rotate/Scale tools, including
the option of numerical input in the channel box.
You could easily rotate a finger of the character in it's complex axis or
make it longer with the scale tool aligned to that axis. You can position things along
custom lines, straighten points to face normals or lines between 2 points
and many other things.
You can also bake the active orientation to the object/s, aligning
object/s local axes along components or quickly transforming the
orientation from one object to another.
You can also scale in screen space using Local Tools. Check "Use
Orientation Only". Enter the tool and instead of picking
compnents/objects go to View --> Select Camera. Now you're able to
scale in screen space.
Don't forget to use HUD shortcuts for accessing the Option Box and locking the pivot.

Reference types:
Point:

Edge:

Face:

2 Point Reference:

Object space reference:

2 Object Reference:

Being able to only inherit the reference orientation:

I forgot to mention that if you select more than 1 component as a
reference, Local Tools is going to average the normals and positions of
the components and use them as the reference (exception being the 2
point reference). This allows you to do things like this:

The option box: (this is an old screen, today I have a much less annoying color scheme).

I've made an online documentation for the tool:
http://www.henrykorol.com/Scripts/LocalTools/LTDocIntroduction.htm
Please visit the download page for the video demo of the tool, I recomend to download the high quality version if you can.