MagLev
http://www.floridatoday.com/news/space/stories/2002b/090802maglev.htm
"The 55-pound sled finishes its journey in the blink of an eye, running about 67 miles an hour. If a full-size "maglifter" is realized, it could cheaply launch shuttles or rockets at speeds of more than 500 miles per hour while
using relatively little energy."
Been awhile since I heard anything about this (a year or two) glad to hear they are still working on it.