crudcutter:
I can't remember whether it was in this Library or somewhere else where I had the misfortune to encounter a complete name swap between two characters.
That might have been in a story I wrote. Yes, I've lost track of who was who, so now I make a list of the characters in the story. I find that really helps.
Another thing it prevents is reusing a name. If Ted is a teacher at a junior college, a different Ted shouldn't a family friend. Not without giving the characters last names and being very clear over which Ted is which. When I need a new name I look at the list of characters and say "Okay, those are taken".
One way I've fond to name characters is from movie credits. Take the first name from a character and the last name of the actor (or the other way around) and you have a character you can picture in your mind.