This critical review covers synthetic ion channels and pores created between January 2004 and December 2005 comprehensively. The discussion of a rich collection of structural motifs may particularly appeal to organic, biological, supramolecular and polymer chemists. Functions addressed include ion selectivity and molecular recognition, as well as responsiveness to light, heat, voltage and membrane composition. The practical applications involved concern certain topics in medicinal chemistry (antibiotics, drug delivery), catalysis and sensing. An introduction to principles and methods is provided for the non-specialist; some new sources of inspiration from fields beyond chemistry are highlighted.