Magnetic nanocrescent Raman probes (see Figure) can not only serve as stand-alone surface-enhanced Raman scattering (SERS) substrates with high local electromagnetic-field enhancement factors, but can also be controlled by external magnetic fields to produce translational and rotational motion of the nanoprobes. Their near-IR optical activities may be useful for biomedical imaging, as near-IR radiation results in deeper tissue penetration and minimal photothermal damage. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2089/2005/c1064_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.