Over at PC World, my latest fun feature looks at some of the most important technologies you never think about.

Consider, for example, the humble battery. We all bemoan the fact that our portable devices don’t last long enough (or, occasionally, that they explode). But have you ever stopped to think how advances in battery technology have changed personal technology? Without modern lithium-ion batteries the iPod would hardly be possible, and your mobile phone would still look like a brick.

Among the other technologies given an airing are XML (it really is everywhere); managed code like Java and Microsoft .Net; and the mysterious world of digital signal processing, where incredibly complex mathematics gets packaged into chips to let you play your MP3s. Who knew?

Check it out and let know what you think.