There is reason to believe that technological approaches can help promote voluntary saving in 401(k) retirement accounts. Working with Vanguard, a leading 401(k) plan administrator, we are evaluating the impact of introducing innovations to websites made available to retirement plan participants. The first innovation is a “Boost Your Saving” dial added to several plan homepages immediately after participants log on. The second innovation is a red/yellow/green “Traffic Signal” that can help people evaluate how well they are prepared for retirement. Our goal is to examine contribution and portfolio allocation patterns in the cross-section and also compare pre/post outcomes. The present report provides a preliminary evaluation of the impact on 401(k) plan saving decisions of the web-based savings dial, designed to increase the salience of retirement saving.  In what follows, we outline the innovation and some preliminary results. We show that including the savings dial on participants’ webpages did boost plan contribution rates. Nevertheless the effect appears to have dissipated after several months, perhaps due to the skewed distribution of participant web logons or to exogenous tax law changes occurring during our evaluation period. We are continuing to evaluate the experiment over time to measure its long-term effects.