In contrast to expensive Treos and BlackBerrys, phones with the extra keys for the Fastap system are only slightly more expensive to manufacture than traditional mobile phones are, according to Levy. Alltel and Telus are offering them to customers at subsidized prices similar to those for their other phones--$9.99, with a long-term contract, in Alltel's case.

Superimposing alphabetic keys on a numeric keypad may sound like a simple idea, but Levy says that some software trickery was required to make it work in practice. The problem is that the Fastap design fits more than twice as many keys into the same area as a traditional keypad. Raising the letter keys gives users tactile feedback that helps them distinguish the letter keys from the number keys. But occasionally, users who intend to press number keys may accidentally press letter keys first, or roll their fingers from number keys onto letter keys.

When adjacent letter and number keys are pressed in quick sequence, algorithms programmed into the Fastap phones always give priority to the lower number keys. Similar algorithms deal with cases in which the users' fingers roll from a number key onto a letter key, or in which two diagonal letter keys are pressed together. Because the software automatically corrects such fumbles, the "touch area" available around each key is effectively the same as that of keys on a laptop computer.

On average, experienced Fastap users write text messages three times faster than triple typers do, Levy claims. He says that users adapt quickly to the alphabetical order of the Fastap keyboard, even if they're accustomed to the QWERTY keyboards of computers and BlackBerry-type devices.

Levy says that Digit Wireless is in negotiations with more mobile-phone manufacturers and carriers, and he expects that Fastap phones will be available soon in Mexico, South America, Europe, and Asia. The company is also exploring alternate bi-level keypad layouts that would accommodate larger alphabets, such as Cyrillic (with 32 letters), Thai (49), and Hindi (60). In those cases, users might have to do some double typing to select the intended letter, Levy says. "But if you go from an average of eight taps down to two, there is still a huge benefit."