Please just use one of the actual bike seats that mount on the bike rather than a trailer. I see people with those child trailers in New York and I just envision a crazy driver not seeing the low largely invisible trailer and running over the kid in a heartbeat. Not much makes me nervous but those trailer seem like death to me in a city like this.

Around my hipster neighborhood most of the fixed dads opt for the standard bike seat or the one that goes on the top tube. That's how I'd roll if I spawned.