  The Wavelength-Oriented Microwave Background Analysis Team (WOMBAT) is
constructing microwave skymaps which will be more realistic than previous
simulations. Our foreground models represent a considerable improvement: where
spatial templates are available for a given foreground, we predict the flux and
spectral index of that component at each place on the sky and estimate the
uncertainties in these quantities. We will produce maps containing simulated
Cosmic Microwave Background anisotropies combined with all major expected
foreground components. The simulated maps will be provided to the cosmology
community as the WOMBAT Challenge, a "hounds and hares" exercise where such
maps can be analyzed to extract cosmological parameters by scientists who are
unaware of their input values. This exercise will test the efficacy of current
foreground subtraction, power spectrum analysis, and parameter estimation
techniques and will help identify the areas most in need of progress.
