There is increasing demand for the development of anhydrous proton conducting electrolytes, most notably to allow the development of fuel cells that can operate at temperatures above 120 degrees C, without the need for constant and controlled humidification. The emerging field of protic ionic liquids (PILs) represents a promising new direction for this research and the development of these materials has made significant progress in recent years. In a related but as yet little-explored avenue, proton conducting organic ionic plastic crystals offer the potential advantage of providing a solid state matrix for anhydrous proton conductivity. Here we discuss the recent progress in these areas and identify the key challenges for future research. (C) 2012 Elsevier Ltd. All rights reserved.