With Skype 3.0, you can place video calls from Skype on the iPhone 4, iPhone 3GS, and 4th-generation iPod touch, and you can receive video calls on the iPad and the 3rd-generation iPod touch. Video calling works over both Wi-Fi and 3G, Skype says.
On iOS devices with two cameras, you can stream video from either. iPhone 3GS users, of course, can only stream video from that device's sole rear-facing camera.
You can use the Skype app to place calls to other folks using the app, or to folks using Skype on their computers. As it did before, the Skype app continues to offer instant messaging, text messaging, audio-only chats, and the ability to call landlines and mobile phones at low rates.
Apple's FaceTime technology is currently limited to Wi-Fi calling only. One might wonder whether Skype's timing for adding video chat to its app might aim to make us forget about the company's recent extended outage, but that would require remembering said outage happened in the first place.
Skype for iPhone is free. Video calling requires iOS 4.0 or later, but the app can run on any device with at least iOS 3.0.