The must-see gadgets from Mobile World Congress 2016 (pictures)

Mobile World Congress is where the hottest wireless gadgets become real. In Barcelona, Spain -- literally a world away from the over-hyped Consumer Electronics Show in Las Vegas, as we like to say -- we spend a week finding the best in new mobile technology.

This year, the world's biggest mobile trade show gave us powerful phones, VR headsets and smart trash cans. Here's what happened on day zero, day one and day two.

Now, let's take a peek at the most intriguing products of MWC 2016, shall we?

HP's Elite X3 smartphone was one of the biggest surprises at Mobile World Congress this year. For one thing, it's an HP phone -- the first since the Palm days. For another, it runs Windows 10 Mobile on a huge 5.96-inch screen with powerful components under the hood. There's a fingerprint sensor and an iris scanner for security.

But the most interesting part of the HP Elite X2 is this: It can dock with peripherals to transform into a Windows 10 laptop or desktop.

No word on price or availability.

Sony phones are coming back to the United States, and the Xperia X Performance sits at the top of the heap. Sony's new line includes three Xperia X smartphones, including the Xperia X and the XA. As the name suggests, the Performance is the most powerful of the three, packing a top-end Qualcomm processor. It's also the only one of the bunch that has the waterproof design we've come to expect from Sony.

There's no word on pricing as yet for the phone, and Sony hasn't been exactly clear on where it will be on sale. We'll update when we hear about wider availability.

Samsung's new Galaxy S7 and Galaxy S7 Edge feature improved cameras, faster performance and longer battery life, among a myriad of other features.

The highlight, however, has to be the return of a microSD card slot and IP68 water-resistant rating, both of which were favorite features that didn't make it into the Galaxy S6.

The S7 and S7 Edge are available March 11, with preorders beginning February 23.

The new LG G5 is a 5.3-inch smartphone featuring a Snapdragon 820 processor and two rear cameras.

It also has one extra feature that may surprise you: a pull-out battery guarded by a snap-off "chin." That part can be swapped out for a variety of modular accessories, including (so far) improved audio and camera modules.

LG hasn't announced an exact release date for the G5 yet, but the company did mention that it will launch sometime in early April.

What's better than a hot new phone? How about a six-wheeled robot that delivers groceries to your door? This robot, by Starship Technologies, can carry up to three bags of groceries. It's covered in cameras (nine of them) to help it avoid obstacles, and can summon a remote operator to help navigate if it gets into trouble.

The HTC Vive VR headset aims to be a "complete set" out of the box, with room sensors, the headset, and controllers included with the $799 system that let you walk around a room and grab things in virtual reality.

That's in contrast to the Oculus Rift, which will only come with a gamepad.

The final retail model of the Vive arrives in early April, and you can preorder the system starting on Monday, February 29.

The Samsung Gear 360 is a twin-lens ball of a camera that captures spherical 30-megapixel photos and not-quite-4K resolution video (3,840x1,920 pixels).

Each of the Gear 360's f/2.0 fisheye lenses covers a 195-degree angle of view that, when stitched together using a Samsung Galaxy S7 (or other select Galaxy phones to be named later), gives you a full 360x180-degree view to explore with a VR headset or by dragging around your fingertips on a touchscreen or your cursor on a computer.

Our contact at Samsung tells us that the Gear 360 is expected to hit in the "first half of 2016", and we expect it to cost at least a few hundred dollars.

The thin, light, attractive MateBook that Huawei introduced at Mobile World Congress obviously takes a few design cues from Apple's iPad Pro, including a folding keyboard case and a pressure-sensitive digital pen for writing or drawing on the screen.

Huawei's, though, comes with a bonus: a built-in laser pointer on one end that you can use to emphatically circle or underscore key points during a presentation -- or just use to drive the feline population nuts.

There will be three models of the MateBook, with price ranging from $699 to $1,599. There's currently no word on pricing in the UK or Australia, but the European prices for those models convert to around £620 and £1,390, or AU$1,245 and AU$2,800. It'll be available in Europe, North America and Asia in the "coming months."

Completely wireless headphones are a pretty new idea, and Motorola might make them work: the company's got a reputation for excellence where stereo Bluetooth headsets are concerned.

The Verveones, which debuted at MWC, fit into a carrying case which doubles as a wireless charger. We can't wait to try them.

So maybe a built-in projector isn't for you. But who hasn't ever wondered if the monsters under your bed or in your closet had returned? Wonder no more, for the rugged Cat S60 has a built-in thermal imaging camera.

Cat's devices are directed towards folks who work in extreme environments, including construction and emergency first response. A thermal imaging camera that can detect heat signatures through walls would likely come in handy for that market segment.

BB-8 from Star Wars is all the rage among cute robot fans, and LG's Rolling Bot is way more advanced than the BB-8 Sphero toy you might have seen.

Thanks to cameras, lasers, speakers, a microphone and plenty of wireless tech built into the rolling chassis, the Rolling Bot is a remote controlled security system, a smart home control, and a pet toy all in the same package.

The LG 360 VR could inspire a whole new wave of virtual reality headsets -- lightweight ones that plug into a phone instead of placing your phone inside the headset.

This one's exclusive to the upcoming LG G5 smartphone for now, but it connects to that handset over a standard USB-C cable.

LG's Cam Plus isn't a camera, but rather a modular grip that slots right into the LG G5 smartphone. In addition to better purchase for your fingers, it offers a dedicated shutter button, zoom dial, and an extended battery for your handset.

The ZTE Spro Plus is a 500 lumen laser projector that doesn't need a single wire. You can fire up the streaming media app of your choice, because it's got a built-in LTE internet connection and runs Android on its high-res touchscreen.

A 12,000mAh battery provides gives you up to a six-hour movie marathon, while built-in JBL speakers provide sound.

Barcelona is installing 200 trash cans that use the low-power Sigfox wireless network to report when they're getting full so the city can empty them sooner -- and not have to send collectors out to trash cans that aren't full.