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I think AddThis(http://www.addthis.com/) solves this problem rather efficiently.

I think DNT+ (http://abine.com/dntdetail.php) also solves this problem...

I use the "Social Widgets" list subscription for Adblock Plus. Just add:

...as a filter subscription in Adblock Plus and you'll stop seeing most of these sorts of "share" buttons.

And sells your data too.