Here's one from the Guitarz archives.
Germany's Gottschall Guitars build acoustics with their patented twin-cutaway funnel body design. Sideways on, the body of the guitar is tapered towards the neck. The insides of the twin cutaways are left open and function as the guitar's soundholes. This allegedly has the effect of increasing the loudness of the guitar by +3 dB.
The guitar pictured is a varition on the doubleneck guitar, it's a double-sided guitar with a nylon-strung guitar on one side and a steel-strung guitar on the other.
The double-sided guitar is not an altogether unique idea. Guitarist Thom Bresh uses a double-sided guitar - The Bresh Dualette - built by Langejans Guitars. This is priced on the Langejans website at $12,995.
Of course, if you can't afford that, Kevin Siebold of Krappy Guitars could build you a "Flipitar" - a double-sided electric - for considerably less.