The eagle-eyed chaps at Inside Facebook spotted a "test" tweet from Facebook engineer Blake Ross, which rather interestingly came from a Twitter client called "penguin FB".
A bit of research found that this runs on Facebook development servers, which would suggest Zuckerberg and co have got something up their sleeves to somehow integrate Twitter into Facey B.
Most interestingly is that Ross's tweet has since been deleted, suggesting there is something to hide. Bit too late there, guys.
If developed and released, the client could well see you being given the option to update your Facebook status, and also publish it to Twitter as well. With 250 million users, this would see Facebook becoming the biggest Twitter client overnight.
Facebook hasn't commented on the story as yet, but we'll keep you updated. Until then, be sure to catch up on our top 10 tips to Twitter success.