I've been looking into "Invisible" apps a lot lately. The concept meshes well with my thoughts on ubiquitous UIs. For the uninitiated, Invisible Apps are those that don't require a visual interface to interact with the service. Most of them involve SMS in some way. You often just text a request or command to the app and they complete it for you behind the scenes. Magic (and GoButler, which appears to be a Magic clone?) and Clara are two of the more interesting apps that I've seen but there is a more complete list with other services that might interest you on Product Hunt.
These apps seem to promise more personal interactions with technology. Although, as evidenced in my screenshot below, I wonder how long it will be before these robots will stop outing themselves. I think maybe you're not real, Ian!