You guys are way off base. The first known use for a "Ranger Band" was when Clayton Moore used one to keep his mask on.

Carry on...

Quiet down separate pieces of gear that would otherwise click, chime, rattle, wear, rub, etcetera, together.

Cover shiny stuff to reduce your visual profile.

Add a rubber grip to the outside of whatever.

A simple and excellent idea. Now I need a source of used inner tubes.

Bicycle shop?

When wrapped around a container seam: holds top on, creates a grip, more water- and dust-resistant, dull down any flash, creates a "pocket" within which to stow other small items, etc,

Any cyclist will have plenty.....

Protect the surface of whatever it is wrapped around [?signal mirror?].

Fasten splints or 'sister' pieces to reinforce / temporarily repair something thin that is broken.