Heise developed this last year. They made a two-stage like-button which is disabled by default and sends no data to FB et al. When you first click on it, the real button loads and you can then share what you want.
That's really interesting. I like the concept, but would most users only click once because that's what they are used to? The interface doesn't seem to be that obvious for a non-technical person.
http://www.heise.de/ct/artikel/2-Klicks-fuer-mehr-Datenschut... [german]