Good advice so far in this thread. It looks to me that secondary journals can be extremely valuable on your resume, but only if you're extensively involved and it's a journal that's directly applicable to your career path (e.g. Employment Law Journal for applications to firms dealing in employees' rights). Of course, law review trumps all, but it seems that it may be just as much a sign of purely academic achievement (as Cady pointed out) as it is a resume-booster in and of itself. In other words, confounding variables and all that.