There's also anisotropic conductive adhesives, which seem to be replacing zebra strips in some applications such as high density LCD connections. They're adhesives (often in a strip form) that conduct up and down but not side to side.
This is achieved by filling them with conductive balls at a density that means they don't touch much, but when the adhesive is pressed into place it collapses in the direction of the pressure. So the lateral spacing doesn't change, maintaining insulation, but the vertical spacing is reduced making a tower of connected balls in that direction.