In what can easily be called an excess of craftmanship, Zipp Speed Weaponry has released these hand-laid carbon fiber water bottle cages.  They weigh in at just 21g and will hold a 30oz bottle.  Zipp says they’re designed for “optimal aerodynamic performance,” just like their wheels…only without dimples (or a nude black version for that matter.  Heck, they could probably shave another gram or two by not painting it).
MSRP is about $60 (or $55 each if you buy two) on the Zipp website, or get your U.S. bike shop to order some through Hawley.