We're a jaded bunch here at Engadget sometimes, and with most of us using SSD-based systems these days it's hard to get too excited about good old spinny disks. Still we're also suckers for impressive technology, so our interest was piqued when Western Digital announced its 5mm thin 2.5-inch hard drives the other day. Luckily, the company saw fit to bring samples of its skinny new WD Black hybrid drive and WD Blue HDD to IDF 2012 and let us handle both briefly. The verdict? These are impossibly thin -- perfect for all those nice Ultrabooks we're expecting to see hit the market in the next few months. Details on performance, availability and pricing are scarce since these drives are intended for OEMs. Take a look at our gallery below, which includes thickness comparisons with WD's upcoming 1TB 7mm thin HDD and a standard-sized loyalty card -- then peek past the break for our hands-on video.