Here are a couple more contour labeling routines to add to the site.
DyamicContourLabeler will allow 2 point selections and dynamically display the elevations of lines, arcs, polylines, and 3d polylines between the points.
(uses ssget->vla-list by CAB)
Label-Contours will allow user to create a polyline path and display elevations at intersection.
(uses ssget->vla-list by CAB and TracePline by Joe Burke)
Maybe someone can find them useful