Architectures of Control, which provides some very interesting analysis of products that are "designed with features that intentionally restrict the way the user can behave" in order to encourage the user to follow certain practices and behaviors, has posted Slanty design, which is a great introduction to the concept and bridges design in the physical world and design for the Web. It's a quick, well illustrated article that I encourage everyone, not just designers to read.For non-designers, it may shed some light as to why some of yoru favorite products and services act as they do.