US Patent 7387457 One-row keyboard and approximate typing

In one aspect, an apparatus for character entry on an electronic device, comprising: a keyboard with one row of keys; and an electronic device in communication with the keyboard; wherein one or more keys on the keyboard has a correspondence with a plurality of characters, wherein the plurality of characters on at least one of said keys includes at least one letter character and one non-letter character, and wherein the correspondence enables touch typing.