Noise Ninja 2.3.2 - Removes image noise & grain from photographs.: "New Noise Ninja plug-in for Photoshop, Photoshop Elements, and compatible hosts. Noise Ninja is the most effective and productive solution for removing noise and grain from digital photographs and scanned film images. It is a must-have tool for anyone shooting in low-light or fast-action situations -- including news, sports, wedding, and event coverage -- where high ISO photography is required and the resulting noise compromises the image.
Noise Ninja often yields a two-stop improvement in effective image quality, while preserving important image detail. In addition, it can produce cleaner, smoother enlargements from low-ISO images."
(Via VersionTracker: Mac OS X.)