There's actually a farm of domestic foxes--I think someplace in England. They were intended to be farmed for fur, but were bred for better behavior (true foxes are very nasty when raised under fur-farm conditions, as would be most any animal, I think). By selectively breeding the tamer, more firendly foxes, they eventually ended up with foxes that were essentially like domestic dogs in behavior--very puppy-ish their entire lives, friendly, etc. Think lab pup, and you're pretty close. The only problem? The selective breeding ignored the coat, and the resulting kits have a mottled fur, red, blue, black and white, looking nothing like a wild fox, more like a merle australian sheppard. I don't know if they continued breeding them or not, but I think this variety of fox would make a fantastic pet. True wild foxes won't--they just are too unpredictable and prone to killing small furry 'friends'.
Skunks, on the other hand, have been domestically bred for a long time. They need to be descented and payed/neutered (apparently a skunk in heat makes a cat in heat look pretty mild). They are easily socialized, box trained, and friendly. The biggest problem is that most states don't have any legal recognition for them as pets, and vaccinations are hard to come by. So, if your pet skunk bites someone, no matter what the provocation, the skunk is most likely going to be confiscated and killed, just like if it were wild and potentially rabid.