An initial glance at the Samsung SPH-A640 doesn't reveal much about what's inside. Even the tiny camera lens located at the top of the handset is relatively unobtrusive. Covering the entire flap is a black plastic face that acts as mirror. Some might like its austerity, but we weren't fans--the plastic feels cheap, and it attracts finger smudges easily. Though you might think there's no external display, a quick press of the volume rocker activates the postage-stamp-size screen in the center of the flap. Though it's monochrome, it displays the date, time, battery life, signal strength, and caller ID (where available). It doesn't support photo caller ID, but it functions as a rudimentary viewfinder for self-portraits. Unfortunately, none of the display settings are customizable.
Inside the phone is the 1.75-inch (128x160 pixels) TFT display. Typical of Samsung displays, it's bright and vivid, with support for 65,000. However, that means it's difficult to see in direct light. You can set the backlighting time, the greeting, the dialing font and size, and the brightness. You also get three menu style choices, and it's one of the first Samsung to show the company's new menus. While previous Samsung menus were known for their animation and graphics-heavy interface, the new menus are designed with simplicity in mind. There's still a bit of animation in one of the styles, but our favorite choice showed only a plain background with a simple grid of choices laying on top. In this case, less is more.
Below a rather large hinge are the navigation controls, which are in typical Samsung style as well. A five-way toggle with an OK button in the center acts as a shortcut to four user-defined functions. There are also two soft keys, a dedicated Back button, and the standard Talk and End/power keys. The backlit keypad buttons are flat of the surface of the phones, but they're big enough and spaced sufficiently far apart. On the left spine is the PTT button, a covered headset jack, and the aforementioned volume rocker, while a camera key and the voice-dialing button sit on the right spine.
The Samsung SPH-A640's phone book is rather small at 300 contacts, but each entry holds five phone numbers, e-mail and Web addresses, a nickname, and a short memo. You can assign callers to groups, pair them with one of 9 monophonic or 20 polyphonic (32-chord) ring tones, or assign them a photo for caller ID. Keep in mind, however, that the image will not show up on the external display. There's also a separate Ready Link address book that holds 200 personal contacts and 200 work contacts. Other dialing features include voice and speed dialing and three-way calling, as well as call forwarding and call waiting. And like the Samsung SPH-A580, the SPH-A640 supports Sprint's new wireless backup service.
The handset's other offerings should be enough to satisfy everyone but the most demanding cell phone users. You'll find a daily event reminder, a scheduler, a task list, a countdown timer, a memo pad, a world clock, a calculator a vibrate mode, text and multimedia messaging, and a speakerphone. There's also Bluetooth for connecting to headsets, but save for an electronic business card, you can't use it for sending files wirelessly.