It depends on the person, the situation and how overwhelmed I've gotten that day. If we're just talking about undemanding cuddling, then with a partner it's fine. If they want to talk at the same time, it won't last very long. I can talk or I can cuddle, not both at the same time. Hand-holding is usually fine, too. Hugs are okay if I know they're coming and know the person. I'm more shy about kissing -- I enjoy it a bit too much, so it had better be leading to something more.
On the other hand, if I've been inundated with people and stress all day, too much physical contact can frazzle my nerves just that much more.