Automatically Organise Your Downloads with Download Sort
Version 2.5.8 of the freeware Download Sort is now available to download.
Download Sort allows Firefox to automatically save your downloads into the folders you define. The rules can be based on a particular file extension, such as .exe or .jpg, or on a keyword found in the file's name. You can further split your downloads into sub-folders based on a download's extension, or date of download. Download Sort can also be configured to display a message in the status bar when the add-on is running.
Please note that the organisational tool requires Firefox 1.5 or higher.