Hm.
From what I've learned about resume design (partly so I could teach resume design to others as a peer writing tutor), modern resumes are supposed to be slick - the guy reviews it for perhaps 30 seconds, and you've got to catch their eye with important stuff on that one scan. Hobbies are not currently considered eye-catching or important, so I've been told to advise others to leave them off a resume.
I've not seen a "hobbies" section on an application in quite some time.
If asked, I don't hesitate in mentioning it. But I don't go out of my way to get them to ask. But then, I occasionally go hiking and camping, and I don't go out of my way to let them know that, either. These days, it seems to me that what one does outside the office isn't generaly a concern to those in the office.