Why and how should I use namespaces in C++?

Question

I have never used namespaces for my code before. (Other than for using STL functions)

1. Other than for avoiding name conflicts, is there any other reason to use

Answer 1

1. Answer: If you ever want to overload the new, placement new, or delete functions you're going to want to do them in a namespace. No one wants to be forced to use your version of new if they don't require the things you require.
2. Yes