methods of populating the simulations with SDSS galaxies using higher order statistics ([*e.g.*]{}, the 3–point correlation function).

Luminous Red Galaxies
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I briefly review here forthcoming surveys of Luminous Red Galaxies (LRGs) as these surveys will soon replace clusters as the most efficient tracers of the large–scale structure in the Universe. Such galaxies are selected to be dominated by an old stellar population (using the SDSS colors) and are luminous, so they can be seen to high redshift even in the SDSS photometric data (see Eisenstein et al. 2001 for details).

A preliminary analysis of the correlation functions for both a sample of LRGs, selected from the SDSS (Eisenstein et al. 2001), and normal SDSS galaxies (Zehavi et al. 2001), demonstrates that, as expected, the LRGs are more strongly clustered than normal galaxies. The LRG correlation function has an amplitude and scale–length consistent with that measured for groups and clusters of galaxies ([*e.g.*]{}, Peacock & Nicholson 1991; Nichol et al. 1992; Collins et al. 2000; Miller 2000; Nichol 2002). Therefore, by design, a large fraction of these LRGs must lie in dense environments as their spatial distribution clearly traces the distribution of clusters and groups in the universe. The main 