The Samsung Jack is a bit of a departure from the Samsung BlackJack and BlackJack II. While it keeps the slim QWERTY candy bar form factor (4.4 inches tall by 2.4 inches wide by 0.5 inch thick and weighs 3.5 ounces), the smartphone features tapered edges and rounder corners to give it an overall look that's more reminiscent of the BlackBerry Curve 8300 series.

It also borrows the mirrored chrome look of the Samsung Propel Pro to give the smartphone an updated, flashier look, but not so flashy that it would look inappropriate in a boardroom. Like its predecessor, the Jack features a 2.4-inch TFT screen that shows 65,000 colors at a 320x240-pixel resolution. It's bright and clear, though it's now starting to look a bit inferior compared to some of the latest messaging smartphones with higher-resolution displays, such as the RIM BlackBerry Curve 8900. As usual, you can customize the Home screen with various background images, themes, and so forth.

Unlike the Samsung Epix, the Jack does not have a touch screen, so the controls below the display will help you navigate the phone. You get two soft keys, a Home shortcut, a back button, Talk and End keys, and a four-way directional keypad with a center select key. With a long press, the Talk and End buttons will also activate the speakerphone and lock the handset. In addition, Samsung added a feature called Turbo Scroll that lets you quickly scroll through an entire page by pressing down on the navigation buttons, while a light press will simply scroll through the text. It's not a revolutionary feature by any means but does come in handy. We had no complaints about the layout or size of the controls and found them quite easy to use. Overall, we were quite pleased with the Samsung Jack's full QWERTY keyboard as well, though there was a slight problem, which we'll get to in a bit.

The Jack ditches the oval-like buttons of its predecessors and goes the way of Propel Pro with rectangular keys. Though there's not a lot of spacing between them, the buttons are a good size and they're not as stiff to press as the BlackJack II's, so we didn't have many mispresses. The only trouble we ran into is that the A button on our review unit seems to be off. Looking at the phone from a profile, we can see that the A key sits a little below the rest and so it requires a really firm press to register the letter and whenever we press the S button, it types an A before the S. We had a feeling we just got a defective phone and had Samsung send us another review unit, and the A key worked just fine on the new one. On the left side, there's a power button and a volume rocker.

Unfortunately, Samsung continues to insist on using its proprietary power/headset port, though the company does include an audio adapter in the box. The camera, self-portrait mirror, and speaker are located on the back, while the microSD expansion slot (accepts up to 16GB cards) is located behind the battery cover. We should note that the battery cover is really slick, which made it quite difficult to remove. This might seem like nitpicking, but it gets annoying when you get to the point where you have to ask for someone else's help in taking off the cover, and even worse, when they go through the same struggles. All that said, we think the Samsung Jack is a nice change of pace from the BlackJack series and we like the fresh look. However, we had a slight preference for the Nokia E71x, given the more solid construction and better user experience of the Nokia. As we noted above, the Samsung Jack is a bit too slippery and the use of proprietary ports is annoying. We wouldn't say these issues are deal breakers, but they're enough for us to slightly favor the E71x.

Of course, style is subjective so your best bet is to go into the store and see which you prefer. With Windows Mobile 6.5 yet to make its debut, the Samsung Jack ships with Windows Mobile 6.1 Standard Edition. Samsung has said that it will offer a Windows Mobile 6.5 upgrade when available but for now, you won't see much of a change from the Samsung BlackJack II in terms of e-mail and productivity and organizational tools. The Microsoft Office Mobile Suite, Direct Push Technology for real-time Outlook synchronization, support for POP3 and IMAP e-mail, instant-messaging clients, a to-do list, RSS reader--it's all in there. Like the Samsung Propel Pro, however, AT&T does include a number of extra applications on the phone, such as MobiTV, My-Cast Weather, eBay, and Mobile Banking. The biggest differences between the Samsung Jack and Samsung BlackJack II are in the processor speed, memory, and camera, all of which get an upgrade. While we'll dive into the processor and memory in the Performance section, we can say now that the Jack's 3.2-megapixel camera is an improvement over the BlackJack II's 2-megapixel lens. This seems like an obvious statement, but it's worth noting because we've seen some 3.2-megapixel camera phones struggle with indoor shots as far as color and the Samsung Jack did pretty well in all aspects of picture quality, including color. Unfortunately, video quality wasn't so great as recorded clips looked a bit blurry and dark. Beyond the camera, the Samsung Jack's features are similar to the Samsung Propel Pro. As a phone, it offers quad-band world roaming, speakerphone, speed dialing, three-way calling, conference calling, voice commands, and threaded text messages, and multimedia messaging. You can also make video calls with AT&T's Video Share service, but note that the recipient must also have a Video Share-compatible phone and the service costs $4.99 per month. Bluetooth 2.0 is also onboard with support for mono and stereo Bluetooth headsets, hands-free kits, object push profile, and personal area networking. The Internet Sharing app will also help you set up the smartphone as a modem for your laptop.

The Jack is a tri-band UMTS/HSDPA (850/1900/2100MHz) device, so in addition to making the Web browsing experience snappier, the 3.5G speeds also help with streaming media services, such as AT&T Music and AT&T Video. Given that 3G can sometimes be spotty and may not be available in all areas, the Samsung Jack also has integrated Wi-Fi to cover your bases. There is an AT&T Wi-Fi utility loaded on the phone, which will give you free access to 17,000 AT&T and Starbucks hot spots. Unfortunately, when we tried to use this service, we were met with a "Coming soon ..." note. That said, we had no problems connecting the Jack to our Wi-Fi access point. We tested the quad-band (GSM 850/900/1800/1900; UMTS/HSDPA 850/1900/2100) Samsung Magnet in San Francisco using AT&T service and call quality was excellent. We enjoyed clear audio on our end with little to no background noise, leading to uninterrupted conversation and trouble-free use of an airline's voice-automated response system. On the other side, our callers also had high praises for sound quality, adding that they couldn't tell we were on a cell phone. Speakerphone quality was also admirable with good sound and ample volume. Finally, we successfully paired the Jack with the Logitech Mobile Traveller Bluetooth headset and the Motorola S9 Bluetooth Active Headphones. As we mentioned previously, the Samsung Jack gets an extra boost from a 528MHz processor and 256MB ROM and 256MB RAM with about 96MB user-accessible storage (compared to the BlackJack II's 260MHz processor and 128MB ROM/256MB RAM). The result is snappy device that handled most tasks without problem and minimal delay. The smartphone's GPS was also quick to find our location and with the aid of AT&T Navigator, provided accurate directions from the Marina District of San Francisco to CNET's downtown headquarters.

AT&T's 3G coverage was a bit temperamental, which led to some frustration as far as Web browsing and streaming media. One minute the Jack would indicate a 3G connection and allow us to watch an AT&T Video clip with synchronized picture and audio and then all of a sudden it would drop to EDGE, making the stream a blurry, choppy mess. In addition, the Internet Explorer Mobile browser is clunky to use compared with others. The Samsung Jack features a 1,480mAh lithium ion battery with a rated talk time of 7 hours and up to 12 days of standby time. We are still conducting our battery drain tests but will update this section as soon as we have final results. According to FCC radiation tests, the Jack has a digital SAR rating of 1.04 watts per kilogram.

Our unlocked GSM cellular phones are only designed to work on GSM networks Only! (such as Cingular, T-Mobile, and others in the U.S.; and Fido and Rogers in Canada).