None of these look particularly easy to use, but ZTE showed off some wild concept devices at Mobile World Congress this year. There were a couple of wristwatches in the mix that unbuckled to become USB modems, but our favorite has to be the "Xer," a handheld "inspired by family theater." It's not clear how you'd hold it effectively if you wanted to type on the QWERTY keyboard, but we suppose that's what makes it a concept instead of a production device. Also shown was the "Pure," featuring a "globoid keypad design" that looks only marginally more usable than the Xer -- or, as ZTE puts it, a "novel key-pressing experience." Click on for the full gallery.