The Travel-o-rama is a large teleporting device built by Gyro Gearloose.
Created in 2001 by Gyro Gearloose to facilitate indoor tourism, the Travel-o-rama has the ability to pull any elements from any place or time period to itself. It is a delicate thing, which didn't take well to a curious Donald Duck pressing a bunch of its buttons at once; the result was the creation of an entirely new, albeit unstable, dimension filled with odds and ends from a variety of places and times (from dinosaurs to Law Robots). Gyro, fortunately, was able to reach into the pocket dimension and pull Donald out of it; as he was the nexus point of the entire time-space structure, this caused the temporal error to right itself, all objects and people going back to their proper time and place.
Behind the scenes
The Travel-o-rama appears in the 2001 story Worlds Apart.
The story is unclear on whether creating customized pocket dimension is part of the purpose of the machine, simply spiraling out of control due to Donald's mishandling, or if it was instead just an unforeseen side-effect and the device is otherwise meant to act as a more traditional teleporter.