Here's an idea I dreamed up of a way to set up a 3D printer as a standalone kiosk.
Have the computer that's running the 3D printer constantly looking in a special DropBox folder. As soon as 3D file is dropped it shows up on a connected tablet or touch screen as a list of print jobs. Simply tap the job to print it.
This allows you to share the 3D printer among several computers or even over the web. You can also set it up so that it can analyze each job and determine a cost to print and won't release the job to the printer until it is paid for. Feel free to add more ideas here: