Robot
With all the whirring, clicking, and beeping, this seems like a natural fit for the self-checks. From a tinny "Scan card now", to a Douglas-Adams-influenced "Glad to be of service", this theme is an efficient and fitting way to welcome our robot overlords.
To install it, please download the self-extracting InstallRobotClayTheme.exe and follow the directions on the instructions page. (There's also a zipped version - InstallRobotClayTheme.zip))
Reedsburg and Sequoya have their own version of the install file.
You may also want to check out the Robot credits page.