Leaping in unannounced to throw my tuppence into the domestication discussion.
Belyaev's foxes are a fantastic view into domestication. Belyaev began strictly breeding caged foxes according to only a single criteria - those that were the least aggressive towards humans and the most willing to interact with humans bred. Within 60 years he's produced a breed of domesticated foxes that sell indivudall for around £4000 and are considered excellent pets, similar to both dogs and cats, and able to integrate well into most households as they will tend to copy the behaviour of other pets in the house.
What he noticed is that breeding for this one trait also produces a lot of the common traits seen in domesticated animals - shorter snouts, shorter limbs, curly tails, black and white markings including spotting and that little star on the forehead, wagging tails started to appear as did barking and licking behaviour.
It is entirely possible that early domestication may have been a somewhat mutual act, rather than us "enslaving" animals. Individuals from herds or packs with genetic mutations giving them less aggression or fear towards humans and more submissive tendencies may have been more likely to be drawn to the abundant food stores humans tended to stockpile. Obviously the humans could have seen the benefit of keeping the animal around, such as with cats that would keep vermin populations down,
*EDIT* Damnit beaten to it DeKaFu
Also: Cuteness!
http://www.sibfox.com/