The BlackJack (or i600N series as we found under the battery) is the first 3G PDA-phone we've seen from Samsung, successor to the GSM-only i320N from last year. We got to play with a BlackJack on the Cingular network at CES 2007 in Las Vegas earlier this year, but in Australia it will be on the Optus, Vodafone and Telstra (Next G) networks, with slight variations and customisations across the range.

Design
Compared to PDA-phones such as the extra-large Dopod 808 Pro, the BlackJack weighs in relatively lightly at 105 grams with the standard battery attached, and measures a thin 11.8mm. Its bright 2.3-inch screen has a QVGA resolution (320x240 pixels) and is landscape-oriented. The BlackJack doesn't have a touch-sensitive screen or stylus; a 4-way directional button, softkeys and a thumbwheel take care of navigation.

Beneath the BlackJack's screen is a QWERTY keypad with a dedicated button for each letter, in contrast to some dual-key QWERTY layouts we've seen like on the BlackBerry Pearl and Sony Ericsson M600i. The BlackJack keypad will be too cramped for those with big thumbs and we found ourselves occasionally hitting the wrong letter by accident as they're so close.

The BlackJack, as its name suggests, is entirely black, bar the silver nav-key and camera mirror on the rear. Samsung also differentiates the number keys on the BlackJack's keypad with grey buttons rather than black. With special characters sharing the limited button space, it's a cluttered-looking but functional keypad.

Features
The BlackJack runs the smartphone version of Microsoft Windows Mobile 5.0, which enables push e-mail -- the instantaneous sending of e-mail to your mobile device -- and synchronisation of contacts, calendar and tasks with Outlook or Entourage. You need to have an e-mail account on Microsoft Exchange Server 2003 (with Service Pack 2) at your work or home office to get this working, though.

Unfortunately the BlackJack doesn't let you edit Office documents; however, you can view formats like Word, Excel, PowerPoint and PDF. That's not to say there's a shortage of applications on the BlackJack. You'll find Internet Explorer for Web browsing, an RSS reader for online news, Solitaire and Bubble Breaker games and a range of organisation apps like notepad, stopwatch, convertor, voice recorder and world clock.

Like the Palm Treo 750, the BlackJack supports high-speed downloads up to 1.8Mbps over 3G, subject to network limitations, but it's not all about business with the BlackJack. Windows Media Player 10 Mobile is onboard to provide some entertainment during downtime. Supported music and video file formats are limited, but still include MP3, WMA and WMV. Third-party applications can be installed for some other formats.

A 1.3-megapixel camera on the back takes stills and up to one hour of sound-enabled video at a time. There's a microSD card slot on the side which supports cards up to 512MB; otherwise there's 35MB to 42MB of user accessible internal memory and 128MB of flash ROM.

Performance
As a messaging device -- the splash screen when you turn the BlackJack on says "The Utra Messaging" -- the drawback is the cramped keypad. We found we often hit two buttons accidentally and couldn't type as fast as we'd have liked. Practice helps and those with small fingers or long fingernails shouldn't have as much of problem.

For $899 outright, Samsung has customised the BlackJack^t, BlackJack^o and BlackJack^v for Telstra, Optus and Vodafone, respectively. The Vodafone and Optus versions have dual cameras and support Wi-Fi (802.11b/g), whereas the Telstra Next G version has a single camera on the back and no Wi-Fi.

All versions support high-speed downloads up to 1.8Mbps, but this is subject to network capability (Optus hasn't rolled out HSDPA 1.8 yet, for instance).

We were sent the Wi-Fi-less BlackJack^t for review so we can't vouch for the battery performance over wireless LAN. We managed three to four days between charges with occasional use of e-mail, SMS, calls and organiser features. Samsung provides an additional long life battery in the Telstra pack and an additional standard battery with the other sales packs.

As a mobile device aimed at business users looking for a balance of work and play, the BlackJack delivers the goods. Provided you get used to the keypad, it performs well as a phone, PDA and messaging device with just a handful of little quirks that deviate from an otherwise solid package.