Enzymes and whole cells are able to catalyze the most complex chemical processes under the most benign experimental and environmental conditions. In this way, enzymes and cells could be excellent catalysts for a much more sustainable chemical industry. However, enzymes and cells also have some limitations for nonbiological applications: fine chemistry, food chemistry, analysis, therapeutics, and so on. Enzymes and cells may be unstable, difficult to handle under nonconventional conditions, poorly selective toward synthetic substrates, and so forth. From this point of view, the transformation—from the laboratory to industry—of chemical processes catalyzed by enzymes and cells may be one of the most complex and exciting goals in biotechnology. For many industrial applications, enzymes and cells have to be immobilized, via very simple and cost-effective prools, in order to be re-used over very long periods of time. From this point of view, immobilization, simplicity, and stabilization have to be strongly related concepts. Over the last 30 years, a number of prools for the immobilization of cells and enzymes have been reported in scientific literature. However, only very few prools are simple and useful enough to greatly improve the functional properties of enzymes and cells, activity, stability, selectivity, and related properties.