MeshToSpline
Creates a spline from the vertices of a mesh object. One possible use would be to recreate a spline object if your spline has accidentally been converted into a mesh (say you collapsed a bunch of objects to editable meshes and didn't realize until it was too late that your spline had been selected too)
View this image to see what this script does...
Installation: Go to Maxscript / Run Script and pick MeshToSpline.mcr ... Then go to Customize / Customize User Interface. Notice the tabs at the top of the screen - go to Toolbars (or whatever you want) and click New to create a new empty toolbar to put the commands in. Now - change the Category to 'CG_Tools' and drag n drop the scripts into the empty toolbar.
Usage: Now just select your mesh object and run the script. Voila. You should now have a spline object whose verts have traced along the mesh verts. I've included an example scene file (max 7) in this zip file called 'Example.max'