After describing a new method of synchronizing spatially separated clocks by means of clock transport, this paper discusses the philosophical import of the existence of such methods, including those of Ellis and Bowman and of Bridgman, with special reference to the Ellis-Bowman claim that “the thesis of the coventionality of distant simultaneity ... is thus either trivialized or refuted.” I argue that the physical facts do not support this philosophical conclusion, and that a substantial part of their argument against Reichenbach, in particular, is misdirected. Finally, I suggest that Ellis and Bowman employ seriously unclear notions of triviality and “good physical reasons” that tend to obscure rather than clarify the basic philosophical issues. An objective criterion of nontriviality of conventions is advanced.