This survey treats two chapters in the theory of log minimal models, namely, the chapter on different notions of models in this theory and the chapter on birational flips, that is, log flips, mainly in dimension 3. Our treatment is based on ideas and results of the second author: his paper on log flips (and also on material from the University of Utah workshop) for the first chapter, and his paper on prelimiting flips (together with surveys of these results by Corti and Iskovskikh) for the second chapter, where a complete proof of the existence of log flips in dimension 3 is given. At present, this proof is the simplest one, and the authors hope that it can be understood by a broad circle of mathematicians. Contents Der Vogelsprecher bin ich ja, Stets lustig heißa hopsassa ! Ich Vogelsprecher bin bekannt bei Alt und Jung im ganzen Land. Weiß mit dem Locken umzugehn und mich aufs Pfeifen zu verstehn !