It's a Planet X Stealth Pro Carbon. It's the same frame Cadel Evans rode in the final 2007 Tour de France Time Trial to a podium finish.
Everything about it is designed for maximum aerodynamic efficiency. The tubes of the frame are aerofoil shaped, and so are the seat post, handlebars and forks. The riding position puts me completely flat, presenting as small as possible a profile to the wind.
The wheels are deep section, that is they have an extended rim that helps reduce drag from the spokes. Additionally, the rear wheel is faired into the frame to further minimise drag.
Next likely purchase: a pointy helmet!