The AddThis extension for Chrome browser is an easy-to-use tool that easily allows me to share, bookmark, print and even translate web pages. With the help of the chrome extension, I find it very easy to share pages to Facebook, tweet to Twitter, stumble on pages, digg favourite pages, blog any page etc.
AddThis supports over 300 services including Facebook, Twitter, Digg, StumbleUpon, Blogger, GMail, Delicious, YahooMail, HotMail, Orkut, AOL Mail Email, Print, Reddit, etc
You can customize the AddThis Chrome plugin via the "Options" so as to personalize the way you share. It is a cool extension to install to your chrome browser instead of installing the different stand-alone plugins for the different social networking and social bookmarking services out there.
I hope this helps...
Feel free to use the comment form to share your favourite plugins.