TechCrunch has posted a brief look inside Google’s Gmail usability lab along with some interesting pictures of the testing and observation rooms. One thing that I found interesting is the large monitor in the testing room–not a typical features in most testing set-ups. Other than that, it’s a pretty standard usability lab. Another thing worth noting is that the usability folks at Gmail rely on Google employees as well as outsiders to test their products. This is an often overlooked testing practice. Even though internal folk can identify major interaction issues at the beginning states of product design, they are often not included in testing. Why not use those easily accessible, free resources?