I know my own boss prefers to initally interview people "over coffee" or someplace other than his office.  Of course, we're fortunate to have a nice little coffee shop in our building which ideal for that sort of thing.

His thinking is that a situation like that is more relaxed, and therefore (as his theory goes) more "honest" and "intuitive".  He claims to get a more accurate reading of a person's personality and "people skills" (which are important in our department) than sitting behind a desk firing questions off a resume.  

There's a time and place the more formal interview, of course, but he prefers to have that later after he has an intitial "read" on the person.  

So far, it seems to work for him.