I listed mine under a section called "pharmacy practice rotations", placed right after work experience. Included: date, nature of the rotation (e.g MICU), rotation site, preceptor. something like this, but formatted
========================================.
. .April 2010 Acute Care Oncology.
.XYZ Medical Center.., Middle of nowhere, Ohio.
. Preceptor: Joe smith, Pharm.D. BCOP
.