The Screamin' Salmon was my fixed-gear bike. A few months ago, after 10 years, I decided to unfix her. I wanted to coast down the Queensboro bridge.
First I put the Bendix 2-speed kickback hub on her, but that hub was too heavy for such a light bike. So then I went with a simple $20 Shimano one-speed coaster brake hub (the Bendix hub was moved to my heavy locked-outside local bike, which is a great match). And I put on 650 wheels (smaller than standard racing wheels) to allow fender clearance. And there's a nice chain guard. I have a rear rack that attaches to the seatpost (not pictured) with panniers for light and medium loads. Plus the Egyptian Spoke Bell (great for Times Square and the bike lane down Broadway). If it weren't for the bell, I probably would have gone with standard hand brakes on the rear wheel. But coaster brakes are also nice because they're weather proof.
I present the Screamin' Salmon to you as a good light fast upright city bike.
It's also probably the coaster-brake bike in the world with bike clipless peddles.
I've fiddled a lot with the bike. I've changed the seat, and the handlebars, and the handlebar stem, and the wheels. I think I've finally got it right.
It may not be the perfect city bike as it goes more for upscale speed than down and dirty carrying. But it meets all the requirements for a good city bike. And as one of my three bikes, it fills a nice niche between racing bike and tank of a bike. I ride this when want to bike to Manhattan and not carry anything on my bike. Or on the rare occasion when I'm wearing something halfway nice and want to arrive looking decent.