You can't say you didn't see this coming, right? Developer Jesse Stay won Kynetx's Facebook App contest with a browser extension that allows you to add Facebook's familiar "Like" button to Twitter.
The browser extension, bearing the name "TwitterBook," uses Facebook's "Like" button iframe code to add the button when you hover over a tweet. "Liked" tweets show up on your profile and allow you to share your favorite posts. The developer is also working on a way to add a "Post to Facebook" checkbox to the Twitter update box. Check the Source Link to grab the extension and give it a test drive.