Marble elevator (hence Marblevator) combined with snap together sectional track and adjustable tressels made using Sketchup 8, ReplicatorG and a Replicator 2 3D printer.
Video of Marbelvator in action at http://www.youtube.com/watch?v=MqLSIlFAPhw.
Video of Marbelvator track with cross unders at http://www.youtube.com/watch?v=0wOupVt8v1c.
Video of a Marblevator track using only 5 track sections at http://www.youtube.com/watch?v=QmMVvP7tny4.
Video of Marblevator using 14mm marbles at http://www.youtube.com/watch?v=7KzasInFa6g.
Video of prototype at http://www.youtube.com/watch?v=pmjuzHZ6XwY.
With the Marbelvator, sectional track and adjustable tressels, an enumerable number of track layouts can be assembled with snap / slide together construction. Print more track sections and tressels and build a bigger Marblevator.