Solid State cologne is a highly concentrated, wax-based cologne made in Melbourne. Most people have probably never used solid cologne, but it’s an excellent addition to your daily carry, toiletry bag, or briefcase.
Solid State is currently available in six appropriately-named scents. My favorite by far was Aviator, while I tried Freshman once and never used it again, though of course your mileage will vary. Each scent has three main notes that make choosing as easy as possible short of Internet-based Smell-O-Vision.
I never travel without solid cologne at this point, and I don’t recommend you do either.