Flip the phone open and you'll note the 2-inch, 65,000-color display. The low 176x220 pixel resolution was a bit disappointing, and we would've preferred a 262,000-color screen. That said, it did look crisper than most other 65,000-color displays we've seen. You can adjust the screen's backlight time, the size and color of the dialing fonts, plus the way the date and time are displayed. Below the display are two soft keys; a four-way navigation toggle that doubles as shortcuts to messaging, instant messaging, the contacts list, and the MyStuff menu; a middle OK key that doubles as a shortcut for the browser; a dedicated Cingular Video key; a dedicated Task Menu shortcut key; the Send and End keys; and the Clear/Back key. While all the keys, including the alphanumeric dialpad, were a little slippery, they were sufficiently raised above the surface so that we could dial by feel.
Though its multimedia features are not as robust as the CU500's, the LG CU400 still has quite a lot to offer feature-wise. The CU400 comes with a 500-entry address book, and each entry is capable of holding up to five numbers, two e-mail addresses, and a memo. Each entry can also be assigned a caller group, one of 10 MP3 ring tones, and a photo for caller ID. Other basic features include a vibrate or silent mode, a flight mode, a speakerphone, a voice memo recorder, Bluetooth, text and multimedia messaging, mobile e-mail (supports Yahoo Mail, Hotmail, and AOL Mail), instant messaging (AOL, MSN, and Yahoo), a wireless Web browser (Cingular calls its Media Net), an alarm clock, a calendar, a notepad, a calculator, a tip calculator, a world clock, a tasks list, a stop watch, a unit converter, a date finder, and a "D-day counter" that counts down to a specific date. As was mentioned earlier, the CU400 is fully compatible with Cingular's PTT network and can hold up to 99 PTT contacts and 30 PTT groups. You can instantly speak with up to 30 people. The CU400 is also a quad-band GSM phone and can be used anywhere in the world.
While it's not a 3.5G phone like its MicroSD-capable CU500 cousin, the CU400 does have support for UMTS, a 3G technology that lets it stream video and music much faster than non-3G phones. Cingular is certainly pushing this with the CU400, especially with its built-in access to Cingular Video, Cingular's 3G content portal with exclusive mobile content from channels like HBO Mobile, plus short clips from networks such as Cartoon Network, CNN, and Fox. Please read our review of Cingular Video for our full run-down of the service. The CU400 video player supports MPEG-4 and RealVideo formats, and you can download video applications such as MobiTV, which lets you watch live streaming TV. Not only that, but you can download other applications such as MySpace Mobile, which lets you keep in touch with your MySpace buddies on the road.
Although the CU400 does not have a digital audio player, you can still access streaming music via MobiRadio and watch streaming music videos on Music Choice. The CU400 also comes with MusicID, a song identification service that lets you know the title of the song just by holding the phone up to a music source, such as a radio. Other music services include Billboard Mobile for industry news, and The Buzz, which is an array of fan communities of certain artists. You can also download XM Radio Mobile if you happen to have an XM radio account so you can listen to satellite radio on the move. It's a shame the CU400 doesn't come with a dedicated audio player, but considering its lack of a MicroSD card slot, it's just as well.
The VGA camera on the CU400 is a considerable step down from the CU500's 1.3-megapixel camera. Camera options include three resolutions (640x480, 320x240, 160x120), three quality settings (Superfine, Fine, Normal), six white balance settings, four color effects, a multishot setting (up to nine shots), a self-timer (up to 10 seconds), and three shutter tones, plus a silent option. Picture quality was quite grainy and blurry, which is what we expected from a VGA camera. The video recorder has two different resolutions (320x240, 176x144) and camcorder options include the same quality, white balance, and color effects settings as with the still camera. We found the video quality to be grainy, choppy, and quite poor in general, but that is pretty normal for a camera phone such as this.
There are quite a few personalization options available for the LG CU400. Not only can you switch out the wallpaper and color schemes, you can also replace the graphics with those taken from the camera or download more from Cingular's Web site. Additional ring tones are also available for download from Cingular. The CU400 supports Java 2.0 games and comes with Diner Dash, World Poker Tour, Ms. Pac-Man, Platinum Sudoku, and Tetris preloaded in the phone, though you can always download more.
We tested the LG CU400 quad-band (850/900/1800/1900; GPRS; UMTS) phone in San Francisco using Cingular's service. Call quality was better than we expected, even in a breezy outdoor environment. Callers did notice we were using a cell phone, but that was not a big deal. You can only activate the speakerphone during a call, and it sounded a bit tinny when activated. As far as Bluetooth pairing goes, we managed to pair it with the Technocel T50 Bluetooth headset without a hitch. Though the UMTS speed is not nearly as fast as HSDPA, we still found it impressive. It took a bit long to connect to certain Web sites, and we suffered slight buffering issues when watching certain Cingular Video clips, but it wasn't unbearable. The video quality was a bit pixilated, but that's to be expected with such a low-resolution display. It took us about eight seconds to download the MySpace Mobile application. It's certainly not broadband speeds, but it's slightly better than dial-up.
The LG CU400 has a rated talk time of as much as 5 hours and a tested talk time of about 4 hours and 15 minutes. It also has a standby time of as long as 12 days. According to FCC radiation tests, the CU400 has a digital SAR rating of 1.14 watts per kilogram.