I'm always looking for DICOM tools to use in practice and for training purposes. After some searching on the web I've located some links to free DICOM tools that could be usefull. I did not test them all so I'm not sure of the quality of the tools, but here they are (if you notice broken links or tools that are not free (anymore) please let me know).
dcm4che is a collection of open source applications and utilities for the healthcare enterprise. At the core of the dcm4che project is a robust implementation of the DICOM standard. The dcm4che-1.x DICOM toolkit is used in many production applications across the world, while the current (2.x) version of the toolkit has been re-architected for high performance and flexibility.