Pilot implementations provide users with real-work experiences of how a system will affect their daily work before the design of the system is finalized. On the basis of a pilot implementation of a system for coordinating the transport of patients by hospital porters, we investigate pilot implementation as a method for participatory design. We find that to foster participation and learning about user needs a pilot implementation must create a space for reflecting on use, in addition to the space for using the pilot system. The space for reflection must also exist during the activities preparing the use of the pilot system because the porters and nurses learned about their needs throughout the pilot implementation, not just during use. Finally, we discuss how the scope and duration of a pilot implementation influence the conditions for participation.