The initial discovery and development of magnetorheological (MR) ™uids is attributed to Jacob Rabinow at the U.S. National Bureau of Standards in the late 1940s [1-3]. Interestingly, even though MR ™uids were introduced almost at the same time as electrorheological (ER) ™uids, more patents and publications were reported in the late 1940s and early 1950s for MR ™uids than for ER ™uids [4]. Until recently, the non-availability of MR ™uids of an acceptable quality has resulted in a dearth of relevant published literature, except for the brief ™urry of publications in the period following their initial discovery. Encouragingly, there has been a resurgence of interest in MR ™uids in recent years.