This addon for the 2.56 beta gives you fingertip control of the 3d cursor. May be helpful in simple CAD drawings of mechanics or architecture. Feel free to try it for yourself.
Some features are finding line-line intersections and 3-point circle center…
Version 0.7.0 for Blender 2.59
Also pushed to svn…
Version 0.6.1 for Blender 2.59
Version 0.4.1 for Blender 2.56ahttp://blenderpythonscripts.wordpress.com/2011/01/09/cursor-control-0-4-1/