  We assess the accuracy with which Omega and Lambda can be measured by
combining various types of upcoming experiments. Useful expressions for the
Fisher information matrix are derived for classical cosmological tests
involving luminosity (eg, SN Ia), angular size, age and number counts. These
geometric probes are found to be quite complementary both to each other and to
inferences from cluster abundance and the cosmic microwave background (CMB).
For instance, a joint analysis of SN Ia and CMB reduces the error bars by about
an order of magnitude compared to a separate analysis of either data set.
