Shareaholic

Social-networking dependents, you know who you are and what you need. The Shareaholic Firefox add-on is primed to satisfy your cravings and compulsion with a few clicks. Essentially a hub for shortcut links to favorite social-networking sites like Facebook, Twitter, Digg, Delicious, Google Reader, FoxieWire, and Plurk, Shareaholic is a Firefox toolbar button that lets you mark or post Web sites and stories by selecting them from a drop-down menu. You can share the page you're on, or even right-click a link on a page to select the Shareaholic sharing options from the context menu.

Of course, Shareaholic lets you customize which of its supported services show up on that drop-down list. We especially liked being able to add notes to our Facebook shares, and to use Shareaholic as a quick way to e-mail links to friends. We had some trouble casting votes with Digg, but transferring links to the other services worked like a charm.