Well, this is interesting. The Skype application for the iPhone and iPod touch has mysteriously vanished from the App Store today. Skype for iPhone was recently updated to allow calls over 3G, but we don't know if this is the reason why it was removed.

It's also strange because Skype was featured on stage during the iOS 4.0 keynote by Apple because it can run in the background. According to TechCrunch, they have contacted Skype, asking why the app was removed, and got the following response:

We’re not seeing the Skype app in the App store. We’re very eager to get to the bottom of this, and I can tell you this has nothing to do with our Verizon deal. The Skype for iPhone app and the Skype Mobile app on Verizon Wireless phones have co-existed.

The Skype for iPhone information pages on Skype's website have not been removed at this time, meaning that this could just be an error.

We'll be sure to keep you posted.

UPDATE: Skype for the iPhone is back in the App Store. No word on why it was removed.