Lenovo's ThinkPad X1 Carbon must still be a hit with the pro laptop crowd, as the PC maker is unveiling no less than three ThinkPad X1 models at CES... and it's shaking up the formula in the process. The headliner is the ThinkPad X1 Tablet (above), which takes a clear stab at the slate-plus-keyboard concept made popular by Microsoft's Surface line. The detachable keyboard and optional stylus are the main hooks, but Lenovo is also introducing unique modules that change the role of the 12-inch machine. A $149 productivity module gives you 5 hours of extra battery, extra ports and wired docking, while a similarly-priced 3D imaging module captures objects. You can even get a $279 projector module, in case you need to make an on-the-spot presentation.