This New York Times article says that people are being asked to stay with family or friends while traveling on company business.

http://www.nytimes.com/2008/10/28/business/28road.html

I can see doing so if you stay with a family member or long-lost friend who is desperate to see you. But in many cases, it would seem like a gross imposition, particularly as there is no suggestion that the family member or friend will be paid for this.

Have you done this? Did you get any extra per diem or some way to compensate your relative or friend?