  Contents:
  1. Introduction
  2. Amphiphilic molecules and the phases they form
  3. Isolated membranes: the Helfrich hamiltonian
  4. Vesicle shapes
  5. Shape fluctuations in vesicles
  6. Interacting fluid membranes
  7. Conclusions
  A. Differential equations for vesicle shapes
  B. The Faddeev-Popov determinant
  C. One-loop calculation of the renormalization group
  D. The Liouville model
