I've actually seen quite a few fox trot routeins... hmm, let me think.... the one that stands out the most would be a routein taht was done to the pink panther theme. It switched back and forth between fox trot and west coast swing.
Plus keep in mind that with showcase routeins, as long as you are moving in time to the music you don't have to have fox trot steps and variations, my best suggestion is to choose your music first and then listen to a few dozen times until you're absolutely sick of it (chances are by the time the showcase is over you'll be sick of it anyway) and just visualize yourself on stage with your partner and see what moves seem to fit in the music. I've actually created new step patterns that way. Just let your mind wander and you'll come up with something. Good luck and break a leg!
~LB
You Haven't Truly Made It Until Your Head Is On A Pez Dispenser