Cosmic complementarity: combining CMB and supernova observations
  We compute the accuracy with which Omega and Lambda can be measured by combining future SN Ia and CMB experiments, deriving a handy expression for the SN Ia Fisher information matrix. The two data sets are found to be highly complementary: a joint analysis reduces the error bars by more than an order of magnitude compared to a separate analysis of either data set. 
Max Tegmark, Daniel J. Eisenstein, Wayne Hu (IAS, Princeton)