If you frequently submit web pages to Google Bookmarks, Digg, StumbleUpon, del.icio.us, and other social bookmarking websites, you'll love the Shareaholic add-on available only for Firefox browser.
Shareaholic make it extremely easy for you to share web pages on the popular social websites - just right click over any webpage and select your favorite bookmarking service from the Firefox contextual menu where you want to share that page.
Even if you are not a big fan of Web 2.0 or social bookmarking phenomenon, Shareaholic still has something interesting for you - it shows you (in real time) the number of people who have saved that web page on del.icio.us and Digg.
Use this information in conjunction with Alexa Sparky to quickly visualize the relative popularity of that web page on the internet.
The service supports reddit, stumbleupon, google bookmarks, digg, del.icio.us, facebook, magnolia, and twitter. Neat alternative to bookmarklets and it also saves you from hunting for those tiny social bookmarking icons on webpages.
Related: Get Rid of Social Bookmarking Icons