The Sony Xperia Z Ultra has been unveiled, bringing with it a huge 6.4-inch Full HD 1920 x 1080 display, as well all the connectivity features and functions you\u2019d expect from a premium smartphone.At only about half an inch smaller than many of the tablets on the market, the most striking thing about the Xperia Z Ultra is how skinny it is. You're not faced with holding a huge fat slab to your face when it comes to making a call, instead it's only 6.5mm thick, so it doesn\u2019t feel quite as awkward as you might expect.Sony Mobile's "omnibalance" design is reflected here as it is in the Sony Xperia Z and the Sony Xperia Tablet Z and the new device looks impressive. There are plenty of 7-inch tablets that you might discount, having set eyes on the Sony Xperia Z Ultra, and lifting the 212g device reinforces this: although it\u2019s weighty in smartphone terms, it isn\u2019t chunky.\u00a0It\u2019s packed full of technology too. This is a fully-fledged phone, offering 4G connectivity, but perhaps admitting that some might not want to hold it against their face all the time, Sony has also launched the SBH52 Smart Bluetooth Handset, an enhanced handsfree kit so you can leave your phone in your bag and still take those calls.Although we've seen a number of great displays this year from the likes of the HTC One, the Sony Xperia Z Ultra has a display that impresses. As a device for browsing the web or watching movies when on your travels, those 6.4 inches obviously give you plenty of space to play.It also looks impressive from the content we've seen so far, but bear in mind we've yet to see how it performs with our own content, or out in daylight conditions.Introducing handwriting support, Sony is claiming that you\u2019ll be able to use a pen or pencil, not just a stylus, if you want to scribble notes. We had a little test using a regular pen and it did indeed work. We\u2019re not sure that everyone will want to do that, especially as Android keyboards are so smart and fast these days.The handset itself measures 179.4 x 92.2 x 6.5mm and you won't have a problem slipping that into a jacket pocket. While it will fit into the pocket of your jeans, it might make it a little awkward to sit down\u2026But this isn't just a huge Sony Xperia handset. It also breaks out a new Qualcomm chipset in the form of the Snapdragon 800. Clocked at 2.2GHz, it takes the crown as being the fastest processor around at the time of writing and we\u2019ve heard from Qualcomm in the past that Snapdragon 800 will do some really impressive things.\u00a0We've not had the chance to really set the Xperia Z Ultra to task, but first impressions are that it\u2019s very fast and snappy. Sony\u2019s early launch cycle - the Xperia Z was launched in January at CES 2013 - often means that Xperia handsets aren\u2019t quite the latest hardware. That changes with this powerhouse, which brings Sony well up to date.Running on Android 4.2 (Jelly Bean), the Sony Xperia Z Ultra has the same customisation that we've seen on previous Sony devices, with a few additions to take advantage of the extra space on offer. We\u2019ll be exploring all the additions in our Sony Xperia Z Ultra review once we have the handset in our hands again.The Xperia Z Ultra is also water resistant, like the other Xperia Z devices, so it won\u2019t mind being dropped in the bath or splashed in the rain. An improvement over the Sony Xperia Z is that the 3.5mm headphone socket is now waterproof too, so you won\u2019t have to be constantly opening and closing a cover each time you want to use it.We\u2019re genuinely excited about the Sony Xperia Z Ultra. It's a huge phone, but at the same time, Sony has done a lot to make the size manageable and we can\u2019t wait to get our hands on it again.\u00a0The Sony Xperia Z Ultra will be launching in September 2013.