If you're a download junkie, keeping all your new files organized can be a challenge. My downloads folder is filled with all kinds of different files, and however often I clean it, it's an inevitably recurring mess. Fluxee (free) is designed to handle this exact problem. It continuously scans a folder, and based on a set of user-defined rules, moves files to a more appropriate location.
Most of Fluxee's functionality lies in the sorting rules. You specify one or more words to search for in the file name (including extension), and a folder to send the matching files. This allows you do things such as move all .avi files to a videos folder, or anything with "company" in the filenme to a work folder. There is also a built-in system for renaming TV files, letting you create a pattern incorporating the season and episode number read from the filename. The interface for setting both of these types of rules appears in a pop-up window. Fluxee's main window contains more general settings, and also a log detailing where files have been moved. It's easy to use and lightweight, even despite its constant scanning.
Fluxee does what it promises, but the absence of more advanced rules for sorting will be frustrating for many users. Fluxee would be a lot more useful if it could read and sort based on music tags and other metadata. If you need to sort based only on filename, then Fluxee is great, and a lot simpler than other similar programs out there. But if you need to dig deeper, choose a more powerful and specialized program like Tag&Rename.