Okay, now, I don't know how good this is, but somebody from the Cafe linked me to a Doctor Who/Firefly crossover that's called "The Man With No Name" for Whoniverse posting and "A Life Less Extraordinary" for Browncoat posting, and I've read the first bit and it seems well enough. SO.

I give you: "The Man With No Name" (http://www.fanfiction.net/s/3486089/1/The_Man_With_No_Name)