If you're a fan of the 'industrial look' then you might want to consider installing this metallic theme on your mobile phone.
The Metal Theme adds a new brushed metal background image to your display, which also incorporates elements of the S60 logo. It will also change the look of your clock-face to a dark gray analog affair.
As well as giving you this new wallpaper, the Metal Theme also changes the icons in the system menu. These blue industrial icon designs didn't really do it for me though, and I find a few of them to be quite ambiguous.
Personally, I reckon the brushed aluminium look is a little dated, but if you disagree then it might be worth having a look at the Metal Theme.