Whatever qualms one might have about a semi-super secret defense agency with a mandate to invent "surprising" military technologies, you have to give the Defense Advanced Research Projects Agency (DARPA) some credit. It's not like with the space program: All they can claim to have contributed to civilian life is Velcro and Tang (and even those claims are disputed). DARPA has given us the Internet, GPS, and faster wireless communications. They failed to give us telepathic spies.
New Scientist looks back at 50 years of DARPA, and comes up with a list of the good, the bad, and the promising. Of course, we'll probably never know about the really good stuff DARPA has managed to come up with.
GPS: We would be quite literally lost without today's global positioning system (GPS). But long before the current NAVSTAR GPS satellites were launched, came a constellation of just five DARPA satellites called Transit. First operational in 1960, they gave US Navy ships hourly location fixes as accurate as 200 metres.
Total failure (but awesome, and immortalized in science fiction):
Orion: Set in motion shortly after DARPA was created, Project Orion aimed to drive an interplanetary spacecraft by periodically dropping nuclear bombs out of its rear end.
The entire craft was designed like a giant shock absorber with the back covered in thick shielding to protect human passengers. Concerns about nuclear fallout and the signing of the Partial Test Ban Treaty ended the project in the early 1960s.
Bionic Limbs: DARPA wants prosthetic limbs that are "fully functional, neurologically controlled and have normal sensory capabilities" and is funding scientists who are making serious progress.
For example, Video of a bionic arm built by the creator of the Segway shows impressive dexterity, while other teams have built prototype prosthetics controlled by thought alone.
Not mentioned, but something I'm pretty pumped about: A nasal spray that dramatically reduces the need for sleep.