Following on a little from the orange On One build up and in particular the Enabler forks / Anything cage combo. I thought this may be of interest.
This is a Bike Buddy, it's a fully adjustable bottle cage but obviously it can hold other things besides bottles. It can be adjusted (by changing springs) to carry things up to 6" in diameter. The whole thing is made in the UK from lightweight stainless steel and there are a few different versions available depending whether you want to fit it to bottle cage mounts or not.
If you want to get your hands on one or just want a better look, go to http://www.bikebuddy.co.uk/ and take a look.