are spontaneously formed by mixing aqueous dispersions of short-“legged” ammonium amphiphiles and fluorescent anions. Energy transfer between donor (naphthalene) and acceptor (anthracene) anions is shown to be more efficient in the hydrogels compared to that in dilute aqueous bilayer dispersions. (N. Kimizuka et al., August 16, Adv. Mater. 2002, 14, 1113-1116)