Acer, Asus, Toshiba, and Lenovo took part in the first wave of ultrabook laptops late last year, releasing impressive systems all less than 18 millimeters thick, and each with second-generation Intel Core i-series processors, and solid-state storage (all required part or Intel\'s ultrabook spec). But, some of the biggest names in mobile computing--HP and Dell--were not among the first movers in this new category (actually a trademarked Intel marketing term). However, both of those PC giants now have 13-inch ultrabooks available, and they\'ve both taken a leading position in our ongoing ultrabook battle royale. Of course, the real competition is still Apple\'s 13-inch MacBook Air--a laptop that has not been updated since summer 2011. We\'re not sure any of these ultrabooks have the Air beat yet, but both the HP Folio 13 and Dell XPS 13 are closer than anything we\'ve seen before. Before you buy, however, remember that with the one-two punch of Windows 8 and Intel\'s next-gen Ivy Bridge CPUs waiting in the wings (although probably not until the second half of the year), all the ultrabooks available right now are in a sense transitional products. But if you\'re looking for an ultrabook right now, we\'ve rounded up the current lineup of product reviews (some other systems are in a same general family, but for one reason or another, don\'t have Intel\'s official stamp of approval to use the ultrabook name-look for them in a future roundup). Compare, contrast, and then let us know which super-slim 13-inch laptop you think is the best. The HP Folio 13 is the best of the bunch in terms of performance, price, and ergonomics, provided you can live with a less-than-razor-thin design Dell XPS 13 Dell packs a 13-inch display into a very small footprint in the XPS 13 ultrabook, making it one of the few slim laptops that actually tops the MacBook Air in some areas. Toshiba Portege Z835-P330 The Toshiba Portege Z835 is incredibly light and offers great bang for the buck in some areas--but it cuts a pretty serious corner by dropping the CPU to an Intel Core i3 Lenovo IdeaPad U300s The less expensive of two available configurations matches up with the low-end MacBook Air, with a 128GB SSD and Intel Core i5 CPU, but the Lenovo is about $100 less, at $1,195 versus $1,299. Acer Aspire S3 Slim, lightweight, and powerful, it certainly looks and feels a good deal like the other ultrabooks. The difference is that Acer has decided to sell the Aspire S3 for $899, a steep discount from what you\'d pay for a 13-inch MacBook Air. Asus Zenbook UX31E If imitation is the sincerest form of flattery, then the MacBook Air should be positively blushing right around now; the Asus Zenbook doesn\'t shy away from an Apple-like design whatsoever. From: Cnet