Caveolae are structures found on the surface of many mammalian cells. In the last few years the biogenesis and the function of these organelles have been intensively investigated but many challenging questions remain. One of these is whether caveolae are statically attached to the cytoplasmic surface of the plasma membrane or are moving to other intracellular organelles. Also the cycling of the caveolar coat component, VIP21-caveolin, is a subject of intensive discussion. The solution to these problems could give an insight into the understanding of caveolar function.