Fujitsu used the Mobile World Congress trade show in Barcelona to show off a tablet keyboard concept that makes do without the keyboard itself.A couple of years ago, Pocket-lint told you about the Light Touch projector that turned any desktop into a virtual keyboard, but the Fujitsu Gesture Keyboard goes one better - you don't need any extra hardware at all.It is a software-based solution that uses the camera in your own device, whether that be a tablet or smartphone. You will need to prop the device up somehow - often upside down, depending on where the lens is situated - and you'll need a well-lit environment, but all the magic is done by the application.Basically, the Gesture Keyboard tracks your fingers and, using the contours of your hands, estimates where the horizontal Qwerty keypad is based. It uses a machine learning technique to determine tapping positions based on a number of factors. First, your finger start positions are important as depth is taken into account. And half the keyboard is assigned to each hand.It can take a bit of getting used to, as the keys are not projected on to the desktop. Instead, you get a visual representation on screen, with the keys you are currently hovering over with your fingers appearing in an augmented reality sense.Basically, it really helps if you can touch type. And even then, there will be differences and new skills to learn.At present, the Fujitsu Gesture Keyboard is a technology concept. But Pocket-lint was told that it will be brought to market some time in the near-ish future. It is not known which operating systems the software will run on, but considering that Fujitsu makes Android and Windows 8 tablets, they will probably be the best bet - initially, at least.