Facebook users in the US can make free phone calls through the social network's iPhone app, thanks to changes in the most recent update.

Facebook users are notoriously sensitive to changes to their beloved social networking service, but something tells us the most recent update to the Facebook iPhone app, version 5.5, may be more popular. This is because it introduces a free phone call feature.

US and Canadian users who update to Facebook version 5.5 can have their calls routed through the app and across the net, eliminating any phone charges (although they'll still have to pay for the data - so look out if you're close to the monthly limit on your data plan!).

As British users we've not been able to try the feature out as yet. Our sources in the US suggest the process works by presenting an icon to ring your friend in the 'now online' screen.

Facebook version 5.5 phone icons

Stay tuned for news on when (and if, sadly) Facebook's free phone call feature will make its debut in the UK. For the time being we can only wait, and feel envious.

Read more about the update over on iPhone Informer.