Skype has finally released an iOS 4 ready version of its Skype app for the iPhone 3GS and iPhone 4, meaning users will be able to multitask with the app and take calls when the app isn't directly open.

"In May, we upgraded our iPhone app to allow users to make calls over 3G data connections. Today, I’m pleased to introduce a brand new version of the app. It allows you to make calls with high quality sound, and supports multitasking", Skype said on a blog post.

The news means that you can now receive Skype calls while other apps are running, even when your iPhone is locked; opening a world of VoIP on demand love and all the headaches for mobile operators like O2 that comes with it.

Skype has also said that it has updated the app’s graphics to support iPhone 4’s retina display.

Even more welcome news, is that the company has also said that it has dropped plans to charge a supplement to make calls over 3G, however has fallen short of adding support for video calling on the new app.

Have you downloaded it? What do you think? Should mobile phone operators be worried? Let us know in the comments below.