The Celio RedFly is a device that connects to Windows Mobile smartphones to give them a readable 800x480-pixel screen and a cramped but usable qwerty keyboard.

In theory, it's possible to do real work such as composing emails and editing Microsoft Office documents on a smartphone. In reality, of course, few people use their smartphones for such tasks because of the small screen and tiny keyboard.

However, Celio's RedFly brings the theory of working on mobile phones much closer to reality. Celio calls its $499 (£250) device a "mobile companion". It connects to Windows Mobile smartphones to give them a readable 800x480-pixel screen and a cramped but usable qwerty keyboard.

The result is a device that's small (25x152x228mm), light (0.9kg) and inexpensive (compared with a laptop) and that has great potential for road warriors and for IT shops that support them. If you're tired of lugging around a heavy laptop just so you can type emails, view Word documents or run PowerPoint presentations, Celio's RedFly can lighten your load considerably.

How RedFly works

The Celio RedFly is neither a laptop nor an ultramobile PC (UMPC), although its screen and keyboard are similar to those of the new generation of ultralight PCs such as the Asus Eee PC 701 and Everex CloudBook.

Rather, the Celio RedFly is more like an old-fashioned dumb terminal without its own CPU or internal storage. In operation it works like a PC remote-access package: you can run any application installed on the connected phone through the Celio RedFly.

Output is displayed on the Celio RedFly's screen. Input occurs via the keyboard and peripherals, such as a mouse, that are attached to the Celio RedFly either wirelessly or via its built-in USB ports.

Besides the Celio RedFly hardware, the other key piece of this system is a small driver that installs on the smartphone. The driver works like remote-access software. It reformats and compresses the smartphone's video output and transmits it via either USB or Bluetooth to the Celio RedFly.

Using the RedFly

The Celio RedFly is easy to use. It boots up instantly and connects with your smartphone quickly. Bluetooth connectivity means you can leave your phone in your pocket or your briefcase while you work on the Celio RedFly. The screen brightness isn't adjustable but, in our tests, we found it to be more than adequate indoors.

The Celio RedFly has two USB ports, which is likely to be enough for most users. Still, you may want to carry a small hub if you need to connect the USB cable, a mouse and a flash drive all at once. And it even has the potential to charge phones when they are connected via a USB cable. So far, though, only two phones from High Tech Computer - the Tilt and the Mogul - support this capability.

There's also a VGA connector on the Celio RedFly so you can attach it to a video projector for your PowerPoint presentation. When you do that, and if you enable Bluetooth on the phone, the phone works as a wireless remote control.

The Celio RedFly looks like a frequent flyer's dream machine. Because it doesn't have a power-sucking processor, its eight hours of rated battery life means it comes close to the road warrior's Holy Grail of being able to work from dawn until dusk. And battery life is likely to be even longer if you don't use a USB cable to connect the device to your phone instead of Bluetooth.

Also adding to its attractiveness is that the Celio RedFly is small enough to fit neatly on an airliner tray table.

The Celio RedFly used for this review was a pre-production prototype - the product will be introduced in the US in April.

>> NEXT PAGE: Drawbacks, a wide appeal and our expert verdict

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The Celio RedFly is a device that connects to Windows Mobile smartphones to give them a readable 800x480-pixel screen and a cramped but usable qwerty keyboard.

The drawbacks

In our tests, the Celio RedFly mostly succeeded in moving the experience of using a smartphone toward that of working on a laptop.

However, there are some drawbacks, most of which result from the fact that, no matter how much the Celio RedFly makes a smartphone work like a laptop, you're still depending on a phone and its limited processor, operating system, applications and storage.

Web surfing is one example. The good news is the Celio RedFly provides a 800x480-pixel screen and keyboard, all significant advantages over a standard smartphone. The bad news is that you're still running Windows Mobile. That platform's Internet Explorer Mobile browser is, arguably, a highly constrained way to browse the web.

Add to that the limited processing power of a smartphone and network access that's likely to be slower than your home broadband connection. The bottom line is a browsing experience that will be much slower than you are accustomed to.

Moreover, while the Celio RedFly does some screen reformatting, many sophisticated websites automatically detect device and browser settings and switch into a "mobile" display mode that presumes a 320x240 display. The resulting paradox is that, the more sophisticated the website, the worse the result on the Celio Redfly.

For instance, in Google's Gmail, the text box for writing an email message stays the same width on the Celio RedFly's screen as it is on a smartphone display. In other words, the text box is less than 300 pixels wide and hugs the left edge of the Celio RedFly's screen.

This problem also afflicts some applications installed in the phone; the more graphics-intensive the app, the less Celio's RedFly can do to remap it to the larger screen. With the Solitaire game on the HTC Tilt used for these tests, the width stayed the same size on both the smartphone and RedFly screens, which made the individual cards smaller than Windows Mobile's icons on the Celio RedFly's screen.

Fortunately, the Office Mobile applications work quite well on the Celio RedFly, using the entire screen. Of course, these are scaled-down versions of Office applications, so they don't include the whole range of formatting options, but the basics are there. Once you've adjusted your typing to the delicate touch required by the smaller Celio RedFly keyboard, you can touch-type in Word at a speed that outruns the display.

Wide appeal

The Celio RedFly's ability to combine wireless connectivity with just enough hardware to do real work should make it a hit not just with road warriors but also with IT departments.

Users will love the Celio RedFly because it can increase productivity. One reason IT departments will love it is that there's nothing to install or maintain on device, and very little training and support is required. As a dumb terminal, there are no security risks if it gets left in a cab. And there's no upgrading required if the user gets a new phone.

While Celio has no immediate plans to provide drivers for other smartphone operating systems, the company says there are no technical barriers to someday expanding beyond Windows Mobile. And some Palm Treo and BlackBerry users will surely clamour for the RedFly, if it becomes available for them.

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Celio RedFly mobile companion: Specs

  • Windows Mobile 5.0/6.0-compatible smartphone companion
  • 8in 800x480 VGA screen
  • 8.3in qwerty keypad
  • 2 x USB 2.0
  • eight-hour battery life
  • 1x6x9in
  • 2lbs
  • Windows Mobile 5.0/6.0-compatible smartphone companion
  • 8in 800x480 VGA screen
  • 8.3in qwerty keypad
  • 2 x USB 2.0
  • eight-hour battery life
  • 1x6x9in
  • 2lbs

OUR VERDICT

Celio's RedFly is yet to be introduced in the US, and we European users may have a long wait – and that's if it even takes off and crosses the pond. We can't help being reminded of Palm's ill-fated Foleo - and at $499 (£250), it is a little pricey. However, the RedFly does a good job of turning your smartphone into a proper laptop to aid productivity, and that's just one of its benefits.

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