Spend some time using 3D design software or exploring your neighborhood with Google Earth while using a traditional mouse and you'll come to a quick realization: While it does a fine job navigating the x and y axes, it doesn't play so well with z. That's not surprising, considering that the traditional mouse was designed to track movement across a two-dimensional surface. Thankfully, for those who spend more than a marginal amount of time computing across the third dimension, devices such as 3Dconnexion's SpaceNavigator for Notebooks ($129.99 list) 3D mouse can make the experience a lot more enjoyable.