The Xperia X8's music player is based around the simple Android default, only with a comprehensive visual skin that goes a long way to making it look and feel a little better than Android 1.6's standard.
The big addition here is the Infinite button, which, when pressed, performs a little automatic internet search for media related to the artist that's currently playing.
It's a bit of a novelty, but if you're listening to a song and fancy having a quick watch of the video, it's a useful shortcut and will bring up a list of YouTube clips on a separate screen for you – and the option to buy it via Sony Ericsson's PlayNow shop, if it's in the catalogue.
The video player is disappointing. Our stock collection of review AVI and WMV files in various Xvid and DivX formats all refused to play, with Sony Ericsson requiring all video to be stuffed on the phone's SD card in a specific MP4 format.
So while music playback is good and the supplied headphones loud and capable, the X8 can't be recommended as a full media player. Having to re-encode videos for mobile use is not what people want from a player in this day and age.
Sadly, with the Xperia X8 being based around the 1.6 version of Android, you're stuck with using the older version of the YouTube client. But it works well enough, with the phone able to handle pausing and skipping with ease.