A few years back, I bought a Korean-made Steinberger Spirit guitar from MusicYo, an online division of Gibson that has since shut down. I originally bought the Steinberger as a travel guitar, but it has since become my main axe. Despite the headless design, it's not as light as other travel guitars, but it is pretty sturdy and has a unique tone and nice sustain. The guitar features EMG pickups and has a great feel. MusicYo is gone now, but you can still find Steinberger Spirits online at eBay, Amazon, and at Musician's Friend and most other online dealers.
Ned Steinberger, a furniture builder from New York, created the unique headless design for his namesake bass back in 1979. He later branched out to create headless guitars built out of graphite and carbon-fibre, but these never broke into the mainstream and he later sold the company to Gibson in 1986. Numerous other headless designs have emerged since the 1980s including Cort, Klein, Hohner, Traveler Guitar, Erlewine and others. Some use an officially licensed version of the Steinberger bridge and tuners, others have their own unique take on things. Ned Steinberger continues to create unique bass cellos, violas and violins in his new company, NS Design.
While these guitars are somewhat hard to come by, they have a devoted following. Musicians famous for using Steinbergers include Lou Reed, Buck Dharma from Blue Oyster Cult, Geddy Lee and Mike Rutherford, who contributed to the design of the original M-Series guitars.
You can also find them occasionally in 80s movies and videos like "Bill & Ted's Excellent Adventure."
Update: I've also added a short video below that shows the Steinberger in action.