Fire Uploader

As the name says, this firefox extension allows you to upload / download files from any website using a friendly interface.

 

In this version, Box.net (1GB of free space), Flickr (photo viewing / sharing), Picasa (photo viewing / sharing), Youtube (Vidoes) are supported.

You can upload videos to Youtube, upload / download / organize photos to Picasa, Flickr and Box.net. Next versions would support other websites like Google Videos, Webshots etc.

http://www.fireuploader.com/