writes "'Evacuated Tube Transport (ETT) is a new kind of transportation system that requires less than two percent of the energy of current transportation methods. It is also much safer, and can be faster. [...] Anyone can visualize 2 tubes (one for each direction) along a travel route. Air is permanently removed from the tubes; so travel takes place without friction. Pressurized passenger capsules (like a 2 - 8 person airplane cabin), travel in the tubes on thin steel wheels or on nearly frictionless Maglev. Airlocks allow access without admitting air to the tubes. Linear motors (as used on new rollercoasters) accelerate the capsules. During most of the trip the capsules coast; using no power. When the capsules slow down, linear generators recover most of the electrical energy used to accelerate the capsules.' Some CG images and drawings here, the FAQ is here."
MSNBC had an article on monorails
a few days ago. Don't bother making Simpsons jokes, the article has them covered already.