The significance of electronic information exchange in inter-organizational cooperation is well-known. We will here focus on the particular requirements of SMEs. We describe a general wrapper agent solution based on open source freeware that makes it possible (in principle) for any business system to exchange information with any other business system. It has been successfully applied in a pilot study involving two companies in a transport chain using different business systems. We also suggest further improvements by addressing security issues as well as an extended, possibly dynamic, set of involved companies and higher levels of cooperation.