The standout design feature is of course the ability to customise the phone's look by adding crystals in a pattern of your choosing. If you're stuck for ideas on how to bling up the phone, Sony Ericsson offers an online gallery for inspiration. The crystal application process is a bit fiddly -- and best achieved with a steady hand and non-bitten-down fingernails -- but once the jewels are affixed, they tend to stay put.
Crystalline gimmickry may be the thing that pulls in the punters, but the general look of the Z300i is similarly slick. The clamshell has an appealing rounded design, is sturdy without being chunky and can easily be operated one-handed.
The look of the phone is easily changed by snapping on a different coloured "Style-Up" cover, which is included in the box.
An ugly and dated-looking external antenna, which has been showing up on a lot of lower-priced clamshells recently, is thankfully omitted in this model, giving the phone a lovely smooth silhouette.
The phone's 128 x 128-pixel, 65K-colour main display was sometimes difficult to read in daylight, and menu icon had jagged edges, but background graphics and games were pleasingly clear and colourful.
The monochrome external screen shows an analogue clock when the phone is closed, and when an incoming call registers, the name of the caller scrolls across the display. The scrolling speed is pretty slow though, meaning that we tended to hold the phone impatiently when calls came in, waiting to discover who was making the blinged thing ring.
The buttons are recessed and sizeable, except for the menu key which is annoyingly dominated by a central select button, making the directional keys hard to get at.
As you would expect from such a modestly priced model, the features are pretty light-on. In addition to basic call and text functions, the Z300i has an organiser, stopwatch, calculator, WAP browser and ringtone composer.
Three games are also included: the innocent but dodgy-sounding "Honey Cave" platformer, a minigolf app, and Black Deal, which teaches the kiddies how to gamble on blackjack hands at a virtual casino table.
The lack of a camera may deter some potential buyers, but is an understandable omission at this bargain basement price.
The main thing we noticed when testing the Z300i was the time lag during texting and address book scrolling. Given that the target audience -- teenagers -- is likely to get pretty SMS-happy, this is a major issue. When we did a fast-fingered test run of text messaging, words took a few milliseconds to appear on screen. While this usually wouldn't be too vexing, letters tended to get left out as a result, so that we had to scroll back through a sentence and edit words.
Compared to other low-priced, plain Jane phones like Vodafone's Simply and the Sagem MyC2-3, the Z300i represents good value for money in a very pretty package. Older novice users can ditch the crystals and still have a sophisticated-looking phone with an easily navigable menu.