Lifehacker's featured Firefox extension yesterday was FireUploader. This is a nifty little extension that allows you to transfer data from your computer to your favorite social media networking sites. The description on the FireUploader site says:
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.
As good as it sounds, I've had significant difficulty making it work right. When I added my Flickr account information the extension crashed Firefox. I continued to get dialogue boxes telling me I was having errors I didn't understand. After a reboot and restart of Firefox all seemed well. I connected to my Box.net account and tried to upload a team policy manual. No dice.
This is an extension I'm going to be keeping my eye one, but it's not ready for prime time yet.