Google introduced +1 Button to make the search more effective

Google has introduced +1 feature to their search results in a way to make the Google search experience more effective and beautiful.
The +1 button is shorthand for "this is pretty cool" or "you should check this out."

Click +1 to publicly give something your stamp of approval. Your +1's can help friends, contacts, and others on the web find the best stuff when they search.

so next time while searching the web you will see +1s from your contacts and even your contacts can see your +1s. Google has said, at the moment one will see recommendations from their Google contacts and soon will be linking with twitter and other services.