The free application, obviously named Wikipedia Mobile, is not the first Wikipedia app in the iTunes App Store but it is the first to be officially sanctioned.
The Wikimedia Foundation which oversees Wikipedia says the app is easier to use than having to jump in to Safari to flick through pages. It's killer feature is keeping your searched pages saved to refer back to.
The Wikipedia Mobile app lacks some of the features available in previous encyclopedia apps on the iTunes App Store but Wikimedia says it was focusing on speed and simplicity for the first release.
You can download the Wikipedia Mobile app for free now from the iTunes App Store. If we see you fondling your iPhone at the Frog And Ferkin pub quiz though, we won't be happy.