Recent advances in our understanding of the cell surfaces strongly rely on new physical methods and concepts. During last decades, microscopy techniques combined with statistical analysis and modelling have significantly improved the toolkit of life scientists. They provide quantitative ways to analyse diverse biological functions such as cell signalling and cell adhesion at different scales. Here, I review quantitative approaches to cell-surface dynamics and mechanics. I focus on two specific topics: how membrane molecules dynamically organize in membranes and how cell-surface mechanics can contribute to tissue morphogenesis.