jEmplode doesn't really officially provide any offline support, but the same codebase as jEmplode is used in another project that essentially is this (basically it "syncs" to a file).... It probably wouldn't be too much effort to let you download your database, then save it to a file, bring it back to life later and then sync it to an Empeg, I guess ... I'd have to play around with the code some to actually get it to do that. Unfortunately this one's not a particularly high priority, so I wouldn't count on it any time soon.