don't we have magnetic acceleration technology?
or at least an understanding of the principles to build some thing like thisby the way the rings in the image are magnets that would be used in a fashion similar to a maglev train.

google space elevator one of the sites has like 205 pictures of proposed lifters/climbers   
http://science.howstuffworks.com/enlarge-image.htm?terms=space+elevators&page=0

well I was thinking that if the electro magnet saw turned on suddenly wouldn't the climber shoot up the cable a short way then the process could be repeated or if the EM interference was great enough it would shoot up all or most of the cable.
Note this would only work for freight as the sudden acceleration would kill a human.

Do electro magnets react in the same way the permeant magnets do with a super conductor?
Which is to say if one had a large enough super conductor couldn't you use it to make the climber go up if it had an electro magnet on it?
let me know if that needs re wording.
EDIT:
In short would it do this