Firefox is still king: creating fully customized GMail and Google skins with plain CSS
Just get the Stylish add-on browse the huge library of community contributed styles to a myriad of sites. My customized Gmail hosted now looks much better (especially on my new small 12.1'' laptop :))
There's built-in support for browsing, searching and managing your styles, very much on the spirit of another great Firefox add-on, Greasemonkey:
Brilliant.
