Houdah Software (http://www.houdah.com/) has updated HoudahSpot, their Spotlight front end for Mac OS X, to version 3.4. The upgrade improves Lion compatibility and brings refinements to many aspects of the product.
HoudahSpot’s tagging feature is based upon the OpenMeta technology, so is compatible with a growing number of third party tagging applications. The HoudahSpot Tray lists favorite tags as well as tags recently used by HoudahSpot or another OpenMeta tagging solution. Drag a file to a tag to assign it that tag. Drag a file to the file well to be presented with a window to enter any number of tags. Select tags and double-click to start a search. Hold down the option key while double-clicking to match any of the selected tags.
HoudahSpot works with Mac OS X 10.5 and higher. It costs US$30 for a single-user license.