Adjustable Height Platform

Take the idea of a space fountain (see link):

Synopsis: Fire ferromagnetic pellets at a platform, the platform extracts momentum from the pellets and generating electricity at the same time. Subsequently, the pellets are turned around and accelerated back to the ground using the energy extracted previously.

Then miniaturize it. The product would be a platform which can be raised to any arbitrary height by firing the pellets. If you enclose the path of the projectiles somehow, you could create a vacuum that eliminates some of the inefficiency. Then mount a camera or anything else from the platform and raise it or lower it as far as you want.

Don't worry about solving all of the problems of a space elevator, just bring it down to a manageable and limited problem. A first step towards development of this project could be to create a "juggling" set of electromagnetic accelerators. One of the accelerators shoots a projectile at the other one, the other receives it and slows it down before shooting it back.