This addon is broken due to API changes as of r53207, but you may use the built-in vertex/edge slide ("GG-slide") instead.
|UI location||View3D > Mesh > Vertices (CTRL V-key)|
|Version||2.0.1||Author(s)||Valter Battioli (ValterVB) and "PKHG"|
|Current version download||https://svn.blender.org/svnroot/bf-extensions/branches/broken_stuff/mesh_vertex_slide.py|
Now work only with Blender 2.62 or higher
Download the script. Put the script in 2.62\scripts\addons_contrib. In the User Preferences, go to the Add-Ons menu. Activate the script. Go to in Edit Mode and press CtrlV then select Vertex Slide.
If you have an error like "global name 'vector' is not defined" you need a more recent version of Blender.
This script allows you to slide a vertex along an edge.
Use ⇧ Shift for slide lower.
One vertex selected
With the Wheel you select wich edge to use for the slide (there is an * near the vertex to move). Every time you change the edge, the slide start from the original position. Hold the left Alt to start the movement from last position, not from original position.
Two vertices selected
With the Wheel you select wich vertex to move (there is an * near the vertex) Every time you change the vertex, the slide start from the original position. Hold the left Alt to start the movement from last position, not from original position. Isn't necessary that the 2 vertices are linked. You can select any vertex in the mesh. If you select more than two vertices, the script don't start.
Press ← to reverse the movement and press → to restore it.
Video with Subtitle (IT and ENG):