Quantum Deformations of Space-Time Symmetries with Mass-Like Deformation Parameter

The difficulties with the measurability of classical space-time distances are considered. We outline the framework of quantum deformations of D=4 space-time symmetries with dimensionfull deformation parameter, and present some recent results.Comment: 4 pages, LaTeX, uses file stwol.sty, to be published in the Proceedings of XXXII International Rochester Conference in High Energy Physics (Warsaw, 24.07-31.07 1996