Multi-kilometer high towers in NASA proposal

http://flightprojects.msfc.nasa.gov/fd02_towers.html

has a proposal for multi-kilometer high towers built with
graphite-epoxy compounds for purposes including power generation and
space launches.

I have not found sources on the nanotech building materials that could
be used as the next iteration after graphite-epoxy.  To the best of my
knowledge, carbon nanotubes are not yet ready for prime time.