Bousso and Polchinski constructed a simplified model of the string landscape, in which different regions of the universe have different vacuum energies, and new vacua are created through bubble nucleation. The probability of our observing a given vacuum energy is the product of the anthropic selection function and the probability P(Λ) of creating a bubble of such a vacuum. I will study this probability distribution P(Λ) in the Bousso-Polchinski model, which is determined by the dynamics of tunneling among the multiple vacua. Since the actual string landscape is expected to be much less ordered than the Bousso-Polchinski landscape, I will explore generalizations of the model, including random perturbations of the vacuum energies. Finally, the reheating of the universe in landscape models will be discussed.