I really think that zombies could exist if some disease were created to affect our central nervous system, something that's very probably to happen. If some people believe in zombies, I think they do it just because they believe on magical arts or vodun religion (where the "Zombie" word was first used also as his meaning).
Actually I don't know anything who joined a zombie cult.
I've never been afraid of zombies, I've always like the idea of a non-rational human, very close to an animal instinct, also, that they are more like immortals and they just want to eat and be fatty!!! Yeyy!!!
I don't really know someone who reminds me a zombie, maybe myself just after wake up and looking the mirror, or some of my friends where one of 'em is drunk and walks unbalanced.