So, you've blocked all your work colleagues from seeing that you're on Facebook chat. Now you can play Scrabulous all day, but how will you know when it's your turn? Enter "Immediate Notifications", which should be showing up on your account from now on.

These are little blue popups in the corner of your screen that'll occur when you're logged in to Facebook chat. They'll show you notifications like "Jim wrote on your wall" and "Bob has played a move in chess, it's your go".

It's yet another move from Facebook which apes the functionality of Twitter. Almost every third-party Twitter client pops up notifications in the bottom-right of the screen in exactly the same way.

Along with recent changes to the news feed to add a big "What's on your mind?" box to the top of the screen, Facebook seems to have ambitions on Twitter's userbase.

However, analysts have commented that until Facebook opens up its "walled garden" approach to data, it'll have trouble capturing people's attention.