Mac OS X only: If Spotlight metadata just doesn't cut it and you want to organise your files by tag, free utility Punakea might be for you. Entering file tags is easy with Punakea: Just drag and drop any files you want to tag either to a pop-up Punakea sidebar, the icon on the Dock, or the app itself. Enter your tags. Then, within Punakea, choose any tag to list its files and also see related tags. In Finder, Punakea actually creates aliases to your files within folders with your tag's name. (You can set Punakea to actually move the files to those folders as well instead of using an alias.) If you're interested in doing more with tags but don't want to get a third party utility involved, check out how guest editor Nick Santilli organizes his files with Spotlight tags. Punakea is a free download with donations requested for Mac Tiger or Leopard only.