Moving a Sofa

I'm not sure what to think of the sorts of brain teasers used in some tech interviews. The Moving Sofa Problem is more my style. I can't imagine anyone solving it in a few minutes in an interview, but there's a nice challenge just in seeing how closely one can guesstimate the solution.

"...it was the mathematician Leo Moser who, in 1966, originally posed the now famous Moving Sofa Problem: What is the largest sofa that can be moved around a right-angled corner in a hallway of unit width?..."

Surfing around on the subject, I stumbled onto a nice page devoted to The Moving Sofa Problem at studyworksonline.com.