Google is just beginning to roll out a new social search feature called Google +1. If you haven’t seen it or caught up on the latest of Google’s social products, then I strongly recommend you read about it via Danny Sullivan’s excellent write up on Search Engine Land, Meet +1: Google’s Answer To The Facebook Like Button. If you’re not seeing these +1 buttons in search results (you need to be logged in to your Google account) then you can opt in to the Experiment.
Essentially, this is a button very much like the Facebook Like button that Facebook launched about a year ago. If you like a web page, you hit the +1 button in Google search results. This applies to both organic search results and paid ads and means that when you are logged in you will see summaries of how many and who (if Google thinks you’re connected to them) +1d them. In a matter of months it’s likely that Google will roll out a button for websites to implement on-site, just like the Facebook Like button and Twitter’s Tweet buttons.