moving line in object w/out changing object

I keep running into the situation where I want an edge of a polygon w/out changing the objects shape. So basically it would move the edge, but the edge would adjust in length to preserve the objects shape. The same thing that happens when you add in a loop cut and decide where to place the loop… the loop adjusts in size as you move it along the object, so the object is not affected.

Is there a hotkey for this? The closest thing I know is shear but thats for rotation only, atleast to my knowledge.

Thanks for the help

Edge Slide ?
http://wiki.blender.org/index.php/Doc:Manual/Modelling/Meshes/Edge_Tools#Edge_Slide

Richard

Thanks a lot, that was perfect