Scouring the wilds of the Internet, I came across this:
The Doctor’s fob watch! From “Human Nature” and “The Family of Blood”!
Supposedly, it even works.
No, you’re not going to be able to store your soul in it, but there’s an actual watch mechanism inside.
Despite not normally wearing a watch, I sort of want it.
And despite not liking the episodes very much, I sort of want it.
It just looks neat.