Wikipedia

According to iPodNN, the current iPad SDK contains additional search options that allow you to choose Wikipedia as one of the default search engines for Safari on the iPhone, iPod touch and iPad. The reference is buried in the code of the iPad SDK, alongside the two other search options. While Safari defaults to Google at present, users can also toggle Yahoo search for a different set of results.

The App Store recently saw yet another augmented reality app get released for the iPhone 3GS. As you can probably guess from the name, Wikitude [App Store, Free] brings Wikipedia into the digitally-enhanced world that is augmented reality. Using it, you can view Wikipedia information about real-world locations while looking at the real world through your iPhone.

Since the App Store first launched, we've seen several applications that attempt to put Wikipedia on your iPhone. Now, the Wikimedia Foundation has released an official Wikipedia application to the app store. It doesn't store data on the device, but it provides a new interface for accessing the online information as an alternative to the mobile version of the website.