The broad shape of the power spectrum of density fluctuations in the evolved universe provides a probe of cosmological parameters that is highly complementary to the CMB and to probes of the expansion history. To harness the improvement in statistical power available from the latest surveys requires stringent control over the effects of non-linear evolution of the matter density field, the relationship between the galaxy and underlying matter density fields and redshift space distortions. Recently it has become possible to reconstruct the so-called halo power spectrum from the Luminous red galaxies of the Data Release 7 of the Sloan Digital Sky Survey. The halo power spectrum has a more direct and robust connection to the underlying linear, real space power spectrum than the power spectrum of the LRG galaxies themselves, making possible a more robust extraction of cosmological constraints from the broad-band shape of the power spectrum. The halo power spectrum also constrains the ratio of the comoving sound horizon at the baryon-drag epoch to an effective distance to z=0.35. Combining the halo power spectrum measurement with the WMAP5 year results, yields interesting constraints on cosmological parameters especially for models that deviate from the minimal LCDM. I will present the latest cosmological constraints obtained from the LRG halo power spectrum alone and in combination with external data sets.