Sometimes you need (), sometimes you don't. Some people 
  think the lack of "unnecessary" parenthesis makes the 
  language more elegant, I just say it makes it harder to 
  determine if something is an attribute or a method, for 
  example.

Well, this is because Ruby, like Objective-C, is a strict OOP language, and there's no such thing as an "attribute" (all instance variables are private). When something looks like an attribute, it's a reader method that returns the attribute.