Looking at Sony Ericsson's current clamshell family (including the youth-focused, party-happy W300i and the achingly cool ), we'd label the Z550i the chic but not showy cousin.
The design is more businesslike than the Walkman branded or mirror-surfaced models, with a brushed metal casing and black accents contributing to the overall sedate look. With dimensions of 45 x 20 x 88mm and a weight of 93 grams, the phone is a compact little number that will sit stealthily in a pocket.
Opening up the clamshell reveals an equally sedate keypad, with comfortably spaced plastic buttons and a round metal navigation button crowning the number keys. Send and End keys, also sleek in brushed metal, flank this circular part.
The 176 x 220-pixel main display looked to be doing justice to all of its 262,000 colours, and passed the sunlight visibility test.
The outer LCD is unusual for its shape and placement -- instead of being a mini version of the internal display, the Z550i's screen is vertically oriented, and at 128 x 36 pixels, more of a strip. Missed call notifications and new message alerts scroll across the screen in purple, along with the name of the person contacting you (or number if they don't occupy a space in your phonebook).
Sony Ericsson has taken a bet each way with the Z550i, offering a sprinkling of business features along with some basic lifestyle and entertainment offerings. For the corporate-minded, push e-mail gets a look-in, as does a sync-able calendar and HTML browser. When you're sick of all the work stuff, you can take snapshots with the 1.3-megapixel camera, play games and listen to music via the media player. The problem is that the phone isn't really optimised for the features it offers -- for example, you'd need to purchase a memory card to be able to store more than a handful of songs, and the screen is too small for anything more than a cursory glance at the Web.