JohnN::

The light weight folding luggage carts they make nowadays collapse into such a small package as to be unobtrusive in most environments.

Just stay away from the small-wheeled versions as they are only useful on evenly paved surfaces.

In previous posts, I have stated a preference for external frame backpacks for myself as you could always add an axle, extendable rigid handle, and wheel setup to them if carrying them on your back becomes a problem.

Bountyhunter