Though the world's biggest mobile tradeshow hasn't offically begun yet, Sunday was a big day for announcements. Samsung, HTC, Huawei, Alcatel, Mozilla and Nokia all held events to bring everyone up to date on what's next for them. And of course, there was a boatload of new products.
Here are the highlights of the day's news and events. (Or all our videos from Mobile World Congress, if you prefer.)
At one of the two events we covered live, Samsung unveiled the two new stars in its Galaxy: the Galaxy S6 and the Galaxy S6 Edge . Going upscale, the new models are built using metal, and the Edge's display extends to wrap around both sides. (As an aside, I have never seen more videos with flying phones than this event.) They'll be available on April 20 in 22 countries and will come in 32GB, 64GB and 128GB versions; thus far, Sprint, AT&T and Cricket Wireless have gone on record as carrying them.
The Edge's edges can glow for notifications so you can see them when it's face down, and touching the heart-rate sensor on the back can send out an autoreply.
The company claims extra toughness, thanks to Gorilla Glass 4 and "stronger" metals than those used in other phones. (Cue bendy iPhone joke.) Samsung also seems to have taken TouchWiz complaints to heart, paring down the user interface and improving responsiveness. For instance, the camera app looks very streamlined., taking a cue from the company's standalone camera interfaces.
The hardware has a 64-bit architecture built using 14nm technology, DDR4 RAM and a combination of new flash memory technologies for better performance and power efficiency. It incorporates a new 5.1-inch, 577 ppi AMOLED display. Plus, the Gear VR has been reworked for the S6 models .
Fully metal Samsung Galaxy S6 looks sharp (pictures)See all photos
Battery charging will theoretically take only 10 minutes for a charge that lasts 4 hours -- it's not removable, though, nor is there a MicroSD slot. It does support wireless charging, using both WPC and PMA standards
The front camera has a 5-megapixel sensor and f1.9 lens plus real-time multishot HDR (for better low-light selfies). The back camera has a 16-megapixel sensor and f1.9 lens with optical image stabilization. The camera is always on standby for fast access and incorporates object-tracking autofocus.
Double-edged sword: Samsung's curved Galaxy S6 Edge (pictures)See all photos
And Samsung takes on Apple in more than just hardware: it debuted Samsung Pay with a bunch of bank partners, a direct challenge to Apple Pay that had been foreshadowed by Samsung's recent acquisition of LoopPay. It's integrated into the two Galaxy S6 models and it will be able to work with old-fashioned swipe readers (magnetic secure transmission), and authenticate with a fingerprint. Wondering what it is and why you should care?
Plus, who expected BlackBerry to pop up at a Samsung press conference? Well, it did in spirit, as part of its plans to create enterprise software to run on more popular mobile platforms; in Samsung's case, it's part of Samsung Knox.
The must-see moments from Samsung's Galaxy S6 event.
HTC's "Utopia in Progress" press conference was an important step in its plans to reinvent itself as more than a phone company. So Say .
Claiming a "ground-breaking" virtual-reality experience, HTC has partnered with Valve (among others, including HBO) for the light, wireless HTC Vive (rhymes with "live") VR goggles that will work with Steam. Vive will ship as a developer's edition in the spring and as a consumer product before the end of the year.
Of course, it also debuted the already-leaked HTC One M9 . In addition to a new two-tone design -- but still all metal with dual front speakers -- the new hardware incorporates a Qualcomm Snapdragon 810, a back camera with a 20-megapixel BSI sensor and sapphire glass, a front camera with 2-micron pixels and an f2 lens, and BoomSound audio with AllPlay support. It will be available in March in four colors: silver, pink, gray and gold.
Up close with the metal curves of HTC's new flagship One M9 (pictures)See all photos
We got to spend a day with the M9's new camera, and well, read for yourself.
Keeping up with the competition, HTC also announced a partnership with Under Armour for its new HTC Grip fitness band. It's got four sensors plus a GPS receiver, and can track walking, running, cycling and gym sessions. It will work with Android or iOS for calls and notifications.
Some tight shots of the HTC Grip (pictures)See all photos
As for software, HTC Sense 7 has a unified photo gallery and new photo effects, plus more customizable themes for the device.
As part of Huawei's bigger brand ambitions, it unveiled the first Android Wear watch incorporating a sapphire crystal display. And with a round display, stainless steel body and mesh wristband, the Huawei Watch isn't ugly.
The new Huawei Watch sports a traditional look (pictures)See all photos
How do you make a phone as cheap as possible? For Huawei, you leave out fast data support. Its Y360 eschews 4G LTE in favor of plain old 3G. But never fear: it also announced a relatively cheap Y635 with the faster standard.
Huawei TalkBand B1 combines a fitness tracker with a Bluetooth headset (hands-on pictures)See all photos
On the fitness-tracking front, the company stuffed an accelerometer into earbuds and boom! -- the TalkBand N1 , which tracks your steps. If you don't like it in your ears, there's also the "bling sprinkled" TalkBand B2 wristband, a more traditional fitness tracker.
Up close with Huawei's bling-sprinkled TalkBand B2 (pictures)See all photos
And finally, the company also introduced the 7-inch MediaPad X2.
Huawei MediaPad X2See all photos
LG's big move today was the unveiling of the LG Watch Urbane LTE , a version of its Watch Urbane that runs -- are you ready for it? -- Web OS! Plus, it supports payments over NFC. AT&T is the first carrier to commit to selling it. But we had to ask: " Is LG's Web OS-based wearable software more than a wacky experiment?"
LG Watch Urbane LTESee all photos
The company also brought us inexpensive small Joy and bigger Leon Android-based phones, plus midpriced biggish and slightly curvy Magna and Spirit models.
New from the veteran laptop company, the 8-inch, Windows-based Ideapad Miix 300 tablet hits a nice budget price point, while the Lenovo Tab 2 A10-70 tablet goes big -- 10.1 inches -- and integrates Dolby audio.
Get a look at Lenovo's Tab 2 A10-70, with Dolby sound (pictures)See all photos
In addition to the tablets , budget Android phones and cheap newbie smartphone it announced the day before the show, Haier won "First!" on Sunday with a new line of connected watches for kids and seniors with handy/creepy monitoring features to let worried parents and children monitor the safety of at-risk individuals. The company also joins companies like Tagg and Motorola in the growing pet-monitoring market with a GPS-equipped collar .
Haier connected watch rangeSee all photos
Acer went light with its Mobile World Congress announcements: its new Android-based Liquid Z and Windows Phone Model M phones won't weigh down your wallet, and the new Liquid Jade Z won't burden your physical pocket much either. It also launched the second generation of its Liquid Leap+ activity tracker.
ZTE eyeballs your eyeballs with its new Eyeprint ID in the Grand S3 , an otherwise ho-hum-sounding phone.
Phone network Orange's Klif Firefox phone will cost $40 and is intended for regions where smartphones aren't ubiquitous, such as the Middle East and Africa.
Alcatel's got a new flagship phone, the Idol 3 , which comes in a 4.7-inch and 5.5-inch versions. The most notable feature is that it autosenses which way you're holding it and flips the operating system display accordingly.
And even more
In an interesting move, Ikea announced a new line of furniture that will support wirelessly charging Qi-compatible devices.
Starting March 2, you'll be able to connect a Withings Activite or Activite Pop watch to an Android phone or tablet.
HP announced a 13.3-inch high-end laptop/tablet hybrid with a fold-back design, the Spectre x360 .
HP Spectre x360See all photos
A close-up with Yezz's modules for Google's Project Ara.
QuindredCam , another lifelogging camera.
SanDisk introduced some high-capacity and touch microSD cards plus some thumb drives with USB connectors designed to connect to Android devices.
Sengled gives us some more multitasking smart lightbulbs .
There's tons more: check out all our photos from the show, and come back tomorrow for more fun.