Something that we've trained Gizmo (and our dog, Cricket) to do is that when someone's coming our direction on the sidewalk, we step off to the side into the grass, and the fox and dog have to either sit or lay down. Cricket is a very big dog, so having her lay down makes her less intimidating.
Well, originally, I was having a really hard time getting Gizmo to lay down like he's supposed to. He would get so over-the-top excited to see someone new that it was all he could manage to hold still, let alone sit down. Finally, we got the idea of walking him and Cricket together, and having him learn from her example; after all, he's mimicked and learned from her multiple times in the past.
To make a long story short, it worked like a charm--whenever anyone approaches us on the sidewalk, Gizmo darts off to the side and lays down like a good boy. But as time has gone on, I've noticed that he's become much better about it than our dog is. She still has to be told (often repeatedly) to lay down, and half the time for my parents she just flat-out refuses to do it. Meanwhile, Gizmo hops off to the side and lays down every single time like clockwork.
Who says you can't train a fox?