You need to install ubiquity. You can download Ubiquity from Ubiquity Mozilla Lab. Verify that Firefox has installed Ubiquity by going to ‘Tools > Add-ons’. You should see Ubiquity listed as one of your add ons.
Just double-click Ubiquity from the add-ons list. Firefox will open Ubiquity tutorial page. Follow the tutorial if you would like to know more about how ubiquity works. Click the ‘Hack Ubiquity’ menu to open the Ubiquity Editor. Copy paste the addToAny.js source code into the command editor and save it a file in your hard disk.
Now we’re ready to use the addToAny command to share on the net. Open any website that you want to share. Next open Ubiquity. Type ‘addToAny to’ follow by the sharing service that you use. If you want to share in Digg you can type: addToAny to digg. Press ‘Enter’. Addtoany will send the website you want to share to digg.
I am really eager to add more customize Ubiquity commands and share it with the rest of Ubiquity user.