Ever had that sinking feeling when using your computer that, in spite of mountains of work to do, you have no idea where the last two hours have gone? It's not hard to get sidetracked by online distractions from Facebook or Flickr to TechRadar or Cricinfo, which is why most of us sometimes need a nudge in the right direction.

Firefox users can now get their productivity push from add-ons like No Links Please that remove all URLs from any page (except Google) in the name of making us focus on the task at hand.

Rod of iron

Admittedly, not being free to surf off down the digital backwaters seems like a punishment at first, but try it for yourself and you'll soon be a convert - we all need rules to live by, after all.

Alternatives to outright imprisonment include scripts like Webolodeon that use nag boxes to pop up and ask you what you think you're doing when there's work to be done. Convince the digital watchdog that you are, in fact, being productive and you're free to carry on.

All said, a new breed of software tools that force us to concentrate might seem a little extreme, but if they help get the job done, then who's complaining? Just ask your boss.