I have purchased the frame, but not yet the Speedhub. For the time being, I've set it up as a fixed-gear, 'cause I was dying to try out the bike, and because I wanted to get a head start on dialing in the position.
Initially I set it up as a freewheeling singlespeed, using a 21 tooth sprocket on an old MTB wheel I had hanging around, with a stack of spacers. That's how it was when the photos were taken.
Subsequently I converted it to fixed by brazing the Freehub body together. I installed a Shimano BMX sprocket on the no-longer-Freehub. With the Campagnolo Mirage crank at 53 teeth, this gives me a 5.7 Gain Ratio (75 inches, 6 meters).