I've seen lots of Android tablets in my day. Even the odd Android-powered laptop. I've seen Android tablets that sort-of try to become laptops. Today, though, we truly have the first one that's able to both — and then some. That beast, of course, is the Lenovo Yoga Book, which the company sent me to take a look at.

It's one part tablet. Another part laptop. Another part futuristic sketch pad. And it pulls off all three in a way that you almost don't expect, given the state of large-form Android devices. But it's pretty easy to nail down just exactly what Lenovo did to create such a unique product.

See at Lenovo

The hardware and that hinge ...

Start with the basics, of course. You've got a 10.1-inch tablet that's impossibly thin, with a gorgeous 1920x1200-resolution display. That's married to a keyboard unlike any that you've ever seen before — because there aren't any keys at all. Instead you get a flat surface on which the outline of keys will present themselves when it's time to type. The rest of the time that area is a high-tech sketchpad, using a souped-up pen to instantly digitize anything you write or draw. It's almost hard to believe how accurate it is, and it turns the worst of scribbles into something that can be stored and manipulated across all kinds of cloud-based ecosystems.

Keeping all that together is the innovative watch-band hinge that Lenovo has made itself famous for. Nothing else looks like that and provides the sort of range of movement. (Never mind that it looks ridiculously cool.) You can easily go from tablet mode to laptop mode to sketchpad mode, with very little effort at all, and without fear of breaking anything in the process. It's as simple as it is innovative.

There's plenty to like under the hood as well. The Yoga Book is powered by an Intel Atom processor, sports 4 gigabytes of RAM, and has 64 gigabytes of storage, with the option for a microSD card to add even more. And the 8500 mAh battery keeps everything powered up. All of this runs Android with aplomb, though there is also a Windows 10 version of the Yoga Book if that's more your thing.

That Real Pen — and that Any Pen ...

For as cool as the hinge is, and as futuristic as that keyboard looks, it's the pen input that's going to grab a lot of folks' attention. But it actually goes way beyond that.

The "Real Pen" is the main method of drawing, writing and digitizing. It's got a more typical stylus nub on it, but you might well want to go with the ballpoint tip so that you can actually put ink to paper while you're putting pixels to the screen.

But then there's "Any Pen" — a technology that lets you take any sort of conductive metal to the display and have it serve as a stylus. Only have a spork handy? So long as it's metal, that half-spoon, half fork will interact with the Yoga Book's display same as the Real Pen. Or a key. Or a knife. You'll obviously want to be a little careful about your writing weapon of choice, but the point is you've got myriad metal options.

The bottom line ...

It's not too often that you get a product that's worth more than the sum of its parts. The Lenovo Yoga Book appears to be one of those, however. You can't overstate the design — just how thin and light and innovative it is. The keyboard has to be seen to be believed. The options for Real Pen and Any Pen add the sort of extras that you won't find anywhere else.

Or boil it down to this — it's just cool. It looks cool. The metal body feels cool. You're going to pull it out of your bag and attract a gaze or two. And you're also going to get stuff done.

And that's truly what it's all about.

See at Lenovo