I will discuss a new, fast method for simulating early structure formation and reionization, without the need for computationally intensive N-body codes. Models of reionization obtainable with this method can be efficiently folded into analyses of current and upcoming high-redshift observations. I adress two such recent studies. Firstly, we examine the potential of using the Lya damping wing imprint in high-z spectra to constrain x_H. We show that the 'picket-fence' absorption typical in realistic inhomogeneous reionization models introduces both scatter and a systematic bias to the measurement of x_H, when compared with the analogous measurement assuming a homogeneously ionized IGM. Secondly, we investigate the impact of source clustering and a patchy reionization on the importance of radiative feedback on atomically-cooled halos. We use a tiered approach: using numerical simulations to calibrate large scale, high resolution semi-numerical simulations. We find that UV radiative feedback has a negligible impact on the evolution of the bulk of reionization, for most reasonable scenarios.
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