Facebook has introduced a Send button which can be added to any website similarly to Facebook Like button. The best part of this is, Facebook Send button can be implemented to the existing code of your Like Button code by just added “send=true” and to disable it, add “send=false”. This should be added right after href like you see below.
If you are doing it for the first time or want a fresh code, Go to Facebook Like Plugin Page, and create your own code. You now have option to select Send there.
What Happens when click on Send Button ?
Send button is like personal sharing or if you want to recommend only to some of your friends. It opens up a message box where you can type in your friends name or email id and send the link along with a message.
For some reason the send button is not working for my site and googling around I see few complaining but it seems like the rollout for the Send button is not complete. As Facebook initially lunched only with Fifty Sites. As of not it is just graying out when the button is clicked and back to normal when clicked again.
If you are a developer, you can get more details on API etc here