Discovery landed in California and a huge Boeing 747 was sent to carry it back to Florida. This $ 1 million one-way trip is illustrated with beautiful photos on the NASA website.
"The SCA (shuttle carrier aircraft) has additional rear stabilizers to minimize turbulence caused by the shuttle on top" (via Digg). The shuttle rode a jumbo jet for the first time in 1977.
Discovery makes pit stop in Oklahoma on its way home - USA Today
Image source: NASA