I have a project that will uses a number of classes some are related but not all, so could I for example, put all my "character" type classes (things like Player, NPC, monsters, animals etc) in a Character namespace and all my XML classes in another (player data, skills, spells etc will all be xml) in an XML namespace etc etc, or is this a bad idea?

I am trying to keep this one as cross platform as possible, which is why its not in C# (I was starting to like it) and in C# that is how I would done it.