1. A file synchronization system comprising: a file synchronization device having, a non-volatile memory for storing a file and at least one bookmark respective to said file, the bookmark indicating a position of presentation within the file, a communication mechanism operative to receive a new bookmark value from a first presentation device, said new bookmark value respective to said file being generated in response to interruption of presentation of the file, and based on a monitored current position of presentation of said file stored in said non-volatile memory when presentation was interrupted, said new bookmark value received separate from and independent of content of said file, a controller operative to update one of said respective at least one bookmark according to said new bookmark value; and to control presentation of said file in accordance with said new bookmark value; and a second presentation device operative to generate a request to present content of said file, and when receiving said new bookmark value from said controller, operative in accordance with said new bookmark value to present content of said file stored in said non-volatile memory from the current position of presentation for said file; wherein the controller is operative, upon receiving the request from the second presentation device, to verify whether the new bookmark value has been received, and if not, to control presentation of said file at the second presentation device in accordance with the one of said respective at least one bookmark.