  This is an extended version of the talk given by the author at the NATO
Advanced Study Institute "Supersymmetry and Trace Formulae" (Isaac Newton
Institute, Cambridge, UK, 8-19 Septemebr 1997). Contains the following
sections:
  1. Eigenfunction correlations in the weak localization regime.
  2. Strong correlations of eigenfunctions and level repulsion at the Anderson
localization transition.
  3. Fluctuations in the addition spectra of quantum dots.
