Starting from the question, what fast electronic transport is based on, and why organic materials in general are more problematic in this respect than typical inorganic ones, methods are introduced that allow to measure the principal material property charge carrier mobility. Some representative experimental results are presented which prove that mobilities around 1-10 cm(2)/Vs can be achieved at I-oem temperature, and more than 100 cm(2)/Vs at low temperature-but only if chemical purity and structural order can be brought to a very high level.