DAPRA plans to have a prototype "tri-phibian" (air, land, sea) zeppelin with a range of 6,000 nautical miles, ready to go aloft by 2008.
The huge airship, about the size of an aicraft carrier, could transport a unit of action (1800 troops, along with their armor and air support) anywhere in the world, without infrastructure, in four days.
The C-130 Hercules cargo plane, holds about 22 tons. Darpa's hoping for a Walrus [the project name] that will someday lug 500 to 1,000 tons.
An earlier A-C-E post (and comment thread) explored a related idea: an airborne-carrier for support aircraft for traditional airborne drops.
See tommorrow's A-C-E post re. efforts of a British firm to build a Sky Cat (as noted by a commenter to this post).