Smart homes have been mostly treated as homogeneous environments where each room is distinguished by the activities performed there but not by any fundamentally different basic parameters for systems to operate in. We argue that at least for bathroom environments, things like the extensive presence of liquid water and humidity and special privacy considerations challenge these assumptions. We discuss typical and unique challenges for ubiquitous computing interfaces in bathroom environments and we look at how actual and conceptual systems confront these challenges. We review bathroom systems in the literature and present two systems of our own to exemplify the unique challenges to smart environments the bathroom provides.