There are only so many ways to lay out the keys on a cell phone for typing words, or so you'd think.

There's the traditional 10-number telephone keypad with the letters of the alphabet bunched three and four to a button. Even with cutsie abbreviations, typing is an arduous affair. If you want a full typewriter keyboard with one letter per key, then you probably have to settle for a bulkier BlackBerry-like device.

Innovative solutions to this stalemate have been rare, and only the BlackBerry 7100 series with its novel two-letters-per-key design can be judged a raging success. Another notable design, from Nokia, with a funky fold-out keyboard resembling a Star Wars wing fighter, has sold well enough to appear on three devices.

The Fastap keyboard from Digit Wireless offers a surprising new twist: The letters appear on 26 small raised buttons positioned at every corner between the standard keys found on a typical cell phone. The letters are placed in alphabetical order rather than the "QWERTY" layout found on typewriters, BlackBerries, Treos and the like.

For now, you can't get a phone with Fastap through one of the big national carriers, but Digit says that's due to change next year. That sounds plausible because the Fastap keyboard is already gaining traction with two smaller wireless providers, Alltel Corp. of Arkansas and Telus Corp. of Canada.

Telus Mobility launched the first handset with Fastap in late 2004, and the customer response has been so encouraging the company has introduced two more models with the keyboard, the third arriving last month.

According to Telus, the Fastap keyboard is fueling higher usage of text messaging and other premium services that generate extra revenue. On average, Fastap users send more than twice as many text messages as Telus customers with a standard phone. Likewise, Fastap handsets generate twice as much revenue from text messaging and mobile Internet usage as comparable handsets.

I tried out the Fastap keyboard on an otherwise ordinary LG handset from Alltel. Without a doubt, typing was swifter compared to the usual process of locating a letter on a number key and then tapping it multiple times to choose from among the three or four letters on that button.

My biggest complaint was that the letters were printed on the keys in a hard-to-read gray. The "Q" key was pretty indistinguishable from the "O" key, and so there were plenty of typos in my messages where a word like "word" was misspelled as "wqrd."

Since it's easy for a thumb to stray onto a number key from the slightly raised perch of a letter button, Fastap is programmed to decide which one the user meant to press. If it comes mid-word, for example, the error-prevention software presumes the number press was accidental, and chooses the letter.

The dedicated letter keys also make it possible to program one or more as a shortcut to an application. On the Alltel phone, for example, holding down the "W" key will launch the Web browser, cutting several key strokes from the process. A carrier can preconfigure these shortcuts or allow users to set their own, a freedom Alltel chose not to provide on its handset.

Another trick enabled by the Fastap keyboard is that you can just dial the letters of a vanity toll free phone number (let's say 1-8XX-NO-SWEAT) instead of hunting for the corresponding letters on the dial pad.

For those who'd prefer a QWERTY keyboard in a phone-sized package, the Nokia E70 may be the way to go, though it may be too pricey for American tastes. You'll need to pay the list price of $450 because the E70 isn't being sold directly by U.S. cellular providers, which unlike foreign carriers have conditioned customers to expect big device discounts in exchange for contract commitments.

The E70, compatible with the Cingular Wireless and T-Mobile USA networks, is a snazzy phone with letter keys far bigger than the buttons on most handheld computers. The hidden keyboard flips out on two hinges over the screen, extending all the way in the other direction to form wings on both ends of the display, with half the letters on either side. When the keyboard is open, a wing gripped in each hand, the display rotates 90 degrees.

Aside from price, another drawback to the E70 may be size, which is a notch bigger in weight and dimensions compared with the two previous Nokia models featuring this keyboard design.

It's rare that you come across a truly novel new approach to an old problem, and if nothing else, the Fastap keyboard is that. It will be interesting to see if this new mouse trap catches on.