It's an unusual, but slim, Walkman handset--technically not a slider, technically not a clamshell, but not a traditional candybar, either. It's got a fold-out flap, like the old-school Ericsson T28 of the early 2000s, which covers the main keypad when not in use.
While this flap is closed, however, you can use some dedicated MP3 player controls that sit on its exterior. The phone's Walkman application is shown while the flap is closed, so you needn't navigate through any menus with these dedicated buttons.
Despite being a fairly low-end Walkman handset (it's only 2.5G, not the speedier 3G), it's very pleasant to use. The keypad is glossy, with large, easy to depress buttons, and the attractive Sony Ericsson GUI makes navigating through features simple.
Inside is only 14MB of memory, but music can be stored on removable Sony Memory Stick Micro cards, and there's a 512MB card in the box. There's also a 1.3-megapixel camera, a 176x220-pixel screen, FM radio, stereo Bluetooth, e-mail, and RSS support, but sadly no 3.5mm headphone socket--you'll have to use the supplied adaptor for plugging in your headphones. For shame, Sony Ericsson.
Music formats supported include MP3 and AAC, but there's no love shown for any subscription services. Naturally you can expect our smashing in-depth review to tell you everything you need to know about its music functionality, and you can expect that very soon, so do check back.