The latest is Hudz, replacement brake hoods that come in a variety of colours allowing you to move away from the standard black coloured hoods that all shifters are fitted with out of the box.
You can choose from 11 colours providing a wealth of options for unique setups, but the most obvious step seems to be matching the hoods to that of your bar tape, as Contador recently demonstrated with all-pink controls. As well as (possibly) improved aesthetics, Hudz also claim to have improved ergonomics, with the Shimano designs receiving the biggest difference from standard - about 6-8m of additional height to the top of the lever hood.
Available to fit Shimano, Campagnolo and SRAM, with the full list of colours including the amusingly titled Bastogne Blue, Bordeaux Gold, Brugge Black, Eroica Celeste, Ghent Grey, Lombardia Orange, Paris Pink, Roubaix Red, San Remo Green, Vlaanderen Yellow, and Wallonne White. Lausanne Clear will be released soon.
Interesting, money from the proceeds will go to a charity, with each colour lending its own individual support to different charities, including the Lance Armstrong Foundation.