I ride a new steel Ciocc roadbike configured as a fixed-gear.
Dedaccia steel with carbon fork, Campi record levers, DuraAce crankset and brakes. The hub is a White Industries "eccentric eno" that allows perfect chain tensioning with vertical dropouts. The gear ratio is 42:15. A relatively high gear number allows me "spin up" to almost anyone on flats and slight uphills. On a 2 to 3% grade I am 10% faster than on my full geared Trek. On 7% grades, I stand the entire climb, which equates to 250 one-legged squats per mile. At 12% you're walking.
The bike weights 18lbs and it is so quiet, you can sneak up on a cat.