Smartphone-lovers are a fortunate bunch right now; if the Apple iPhone 4 doesn't take your fancy, there's plenty of Android phone alternatives, and if neither of those options satisfy your mobile needs either, a slew of new Windows Phone 7 handsets might just win you over instead.

If you're still not inspired, there will no doubt be a slew of new handsets hitting shelves in the months after Mobile World Congress.

Despite this veritable barrage of all-doing, app-consuming devices, there are those who are already dreaming up how the next must-have mobile could take shape. From the creative minds of some of the industry's leading innovators, to the imaginations of design students, here's our pick of the concept phones we'd love to see created.