The Infineon application note AP292501 http://www.infineon.com/cmc_upload/migrated_files/document_files/Application_Notes/AP292501.pdf describes the problem and two commonly used methods to solve this problem.
On the next ICC 2003 Uwe Koppe (MicroControl) presents: Automatic bit-rate detection in CANopen networks.
The CiA has published an application note based on the Koppe paper: CiA AN 801 V1.0: CANopen automatic bit-rate detection It can be downloaded at the CiA document page: http://www.can-cia.org/downloads/ciaspecifications/
Some of the CanOpen drivers of port_GmbH are supporting auto bit rate detection.