There's something about the D840 that screams Mercedes Benz. The curved metallic details on the front look as though they've been ripped off a brand-new E-Class. Fortunately, unlike a Mercedes, the D840 is very pocket-friendly, measuring only 12mm thin.
You can buy the D840 for free on a monthly contract from Carphone Warehouse, Orange or Vodafone.
You wouldn't be mistaken for thinking the Samsung D840 bears an uncanny resemblance to the LG Shine. It's thin, it's silver and it has a reflective screen, but this Korean-made handset is no doppelganger. Its screen isn't as reflective as the Shine's, there's no scroll bar and it's slightly thinner.
On closer inspection, you'll notice that the D840 is actually much more similar to its older relative the, which had a similar casing but lacked the silver paint job -- and was slightly thicker, too.
Due to its thinness, the D840 felt comfortable in our trouser pockets and it didn't feel too heavy either. It's wide enough that you don't need to grip it with a pair of tweezers to make a call though, and it won't feel as though you're holding a chopstick to the side of your face either.
For such a thin phone, it's great to see that accessing the expandable microSD slot is really easy, as it's not inconveniently positioned behind the battery but instead placed on the right side of the phone.
The slide mechanism is really smooth and there's a handy ridge just underneath the screen to push the top section open. Further down the top section there's a four-way navigation button with an okay button in the middle, marked 'i'. Annoyingly, the i button will take you to the Web browser from the start page and not the menu.
Hidden behind the top section is a completely flat keypad. Relative to other flat keypads, like the one on the LG Shine, we found it okay to use. It's more difficult, however, to distinguish clearly between each key compared to a keypad with more defined and protruding keys.
Our only other design niggle with the D840, other than the small cancel key and flat keypad, is the camera on the back, which juts out and ruins the smooth lines of the rest of the phone.
Eight months ago, the Samsung D840 would have been a cutting-edge phone in terms of features. Indeed, it has an almost identical feature set to the Samsung E900, which came out in July last year. Unfortunately, compared to the latest handsets it's a little lacklustre.
The 2-megapixel camera is dated compared to the D900's 3-megapixel one, and it doesn't have auto-focus, which means photos come out blurry if you move while taking one. The LED photo light isn't particularly good, only working at close range.
The music player supports MP3, ACC, ACC+ and e-AAC+ formats. You can listen to music via the loudspeaker, or you can use the proprietary headphones. Unfortunately, it doesn't come with a 3.5mm jack adaptor and you can only use the proprietary headphones, which don't come with any MP3 controls built in. There's also no FM radio, a feature lacking on many Samsung phones.
Aside from these issues already mentioned there are a few smaller flaws that might annoy you. For example, there are only two skins (also known as themes) that you can set to either black or white, and you're limited to ten message tones without the choice to add your own.
You also can't set MP3 ring tones to vibrate and only certain tones will ring and vibrate at the same time.
Samsung has come up with a natty way of navigating menus, however. As you scroll through the list of options, a window pops up listing the options on the submenu. Pressing the number relating to the submenu option takes you straight there, which speeds things up slightly.
Other features of note are the speakerphone mode, Bluetooth, SMS and MMS messaging, a voice recorder, polyphonic ring tones, a calendar, a to-do list, a scheduler, a clock, world time, an alarm, a timer, a stopwatch, a calculator, a currency converter and Java games.
The battery life is quoted at 2.8 hours talk time and 295 hours standby time. We found that it lasted for about two days before we had to recharge it.
Audio quality during calls was loud but not always crystal clear. The audio quality from the music player was acceptable, but as you're stuck with using the provided headphones you can't expect much better. The speakerphone mode sounded tinny and not particularly clear.
The 2-megapixel camera took relatively decent pictures if you intend to send them to other phones via MMS or Bluetooth, but when viewed on a computer screen they invariably looked blurry.
If you're looking for a thin and stylish slider phone, then the D840 is worth checking out, but overall we don't think it's as cool as the LG Shine. Features-wise, the Samsung D840 didn't really impress us, especially if you compare it to Samsung's other thin slider phone, the .
Indeed, the D840 shares a similar feature set to the Samsung X820, minus the expandable memory card slot. If it's a thin phone you're after we think it's worth looking at the, which measures a minuscule 6.9mm thick and will practically do all the things the D840 can do.
Alternatively, if it's an envy-inducing fashion phone you're after, then you might want to check out the.
Edited by Jason Jenkins
Additional editing by Nick Hide