ShapeShifter
The script is 'sort of' a spline normalizer with a little different twist. It also has limited functionality when used on nurbs curves. All actions are based on a calculation between total spline length and 'travel' length. So basically we 'travel' down a splineshape while creating a new spline - adding knots at 'travel' length increments until we reach the end of the subject splineshape. This creates a new splineshape that can be similar to the original or quite different but with a relationship to the subject splineshape. The idea was more to 'equalize' segment lengths - rather than to have strict lengths enforced. Playing with it using primitive shapes can be quite interesting - creating other primitives from a circle - for example - N-Gons using the 'corner' option. Be sure to try the 'Example' button.
Written using Max 7.x
Very limited testing in Max6 & Max5.1 but it seems to work.
Enjoy! And thanks to all who share their scripts!
To execute place the script in a directory - Go to the Utilities Tab - Maxscript/Run - navigate and select 'ShapeShifter.ms'
Larry Mintons AVG_DLX extension is not required - but does add greatly to the functionality. I reccommend it.