Local Chicagoan and blogger Jason Fried of Signal vs. Noise has a nice little post on the Farnsworth House (aka. Mies van der Rohe's house of glass) as well as some nice pictures. I'm going to have to take a trip out there myself someday soon. It's only an hour or so from downtown Chicago
"I pointed out to him (Mies) that it (a glass house) was impossible because you had to have rooms, and that meant solid walls up against the glass, which ruined the whole point. Mies said, 'I think it can be done.'"Farnsworth House by Mies van der Rohe (Plano, IL) (Signal vs. Noise)
— Philip Johnson speaking at a symposium held at the School of Architecture, Columbia University, 1961.
Be sure to check out the excellent information at farnsworthhouse.org.