Branding Iron for Mac

From Aero Quartet:

Spotlight is nice to search by keywords, but doesn't let you associate arbitrary keywords to your files. With Branding Iron, you can mark your files and get the most out of Spotlight and Smart Folders. Imagine you want to label a dozen of files as belonging to "Project Brinkman". The traditional way to organize them is to put them in a folder called Project Brinkman But now, with Branding Iron and Spotlight, you can just mark them, store them in whatever folder or hard disk (for example, by category : Accounting, Budget, Engineering, Artworks, ...) and then create a Smart Folder called "Project Brinkman". Automagically, your files will be here. You can move them, modify them, rename them. They will be marked forever.