Lenovo's ThinkPad X1 (bottom) and Edge E220s (top) are two of the sleeker, thinner ThinkPad laptops we've seen lately. The X1's got a sturdier construction, but a wider base and bigger screen. The Edge E220s feels more like a slightly larger Netbook.
The most dramatic difference comes with the lids open. The subtle variance in dimensions amounts to a significantly smaller laptop with the Edge E220s, which could make the difference when working on a cramped airplane fold-down tray.