Set in a mirrored frame, the postage stamp-size external display shows the date, time, battery life, signal strength, and caller ID (where available). Though it supports a relatively low-res 4,096 colors, it's still vibrant and bright. Below the screen is the camera lens. There's no self-portrait mirror, but you can use the external display as a viewfinder with the flip closed. The only thing we really missed was a camera flash. A dedicated camera buttons sits on the left spine just above the volume rocker and the infrared port, while the speaker rests on the phone's rear face.
Inside the phone is the outstanding 65,536-color internal screen. Sony Ericsson excels at designing rich displays, and the Z520a is no exception. The screen measures just less than 2 inches diagonally, but given the phone's small size, it's ideal for browsing through the user-friendly menus, playing games, and viewing photos. You can alter the brightness but not the contrast or the font size. Below the display are the navigation controls, which consist of a five-way toggle, two soft keys, a dedicated Back button, and a dedicated Clear key. As is the case with all Sony Ericsson phones, there are no dedicated Talk and End buttons. Though they keys are large and tactile, the toggle and the OK button are rather small, so users with large digits should take note. What's more, because the keys are flush with the surface of the phone, it's easy to scroll in an unintended direction.
Sony Ericsson usually stumbles when it comes to cell phone keypads, but the company finally struck the right chord with the Z520a. The beveled keys are well spaced and adequately sized, so it's easy to dial by feel. Also, a bright blue backlight makes it easy to dial in darker environments. The plastic casing surrounding the keypad holds eight evenly spaced lights that flash during incoming calls. It's an unusual but cool feature, and the color matches the keypad backlight. You can choose from six patterns or turn it off completely. At the bottom of the phone are a power button and a dedicated control for activating the Web browser.The Sony Ericsson Z520a offers all the features you'd expect from a midrange cell phone. The 500-contact phone book is small, but you can save an additional 250 names on the SIM card. Each entry holds five phone numbers, an e-mail address, a Web address, a street address, job title and company, birthday, and notes. You can organize contacts into caller groups, and for caller ID purposes, you can pair them with a picture that will show up on the external display. We were surprised at the number of included polyphonic (40-chord) ring tones and sounds: 46 in all. The Z520a's MP3 support means you can download additional tunes from Cingular via the WAP 2.0 wireless Web browser. Other features include a vibrate mode, an alarm clock, a world clock, a calculator, a stopwatch, a timer, a notepad, PC syncing for your contacts, a tasks list, a calendar, text and multimedia messaging, and a code memo for storing sensitive information such as your bank account PIN number. The speakerphone is always a welcome inclusion, but you can turn it on only after you make a call. More demanding users will appreciate the infrared port, a wireless business-card exchange, POP3 and IMAP4 e-mail support, and Bluetooth for calls and file transfers.