Google reader has added “sharing” for stories you feel should be shared via other websites (besides just their “share with your followers option”).
Icon URL: http://www.iconfinder.net/data/icons/sociolego/128/mixx_lego_128.png
The icon is for a lego version of the Mixx icon. Good enough for me!
I’m using these sharing options: Ping, Reddit, Tumblr, and now (thanks to my quick setup) Mixx.