Autofill Forms - With Google toolbar out of commission I had nothing to do autofill in FF3. When searching for a replacement I came upon this. I tried this years ago and its was crap at the time, now after a lot improvement and changes, it is one of my favorite extensions. The best part is that it can be activated by a icon in the status bar or keyboard shortcut, so you don't have to add another toolbar button.
BlueOrganizer - This extension does a ton including submit page to Digg. Lets say your
looking a DVD to buy on Amazon. This extension will provide you not only with link to other retail sites' pages for that same DVD but it will also provide connection page for reviews of the movie and a Netflix page in case you want to rent it instead. It does thing for almost any product and something similar for people. Lets say your looking at someone's Facebook profile, it provide you link to their pages on other sites like Flickr. This is only the begging of what it can do check it out yourself if your interested.
