Skype team officially announced Skype for iPhone & iTouch. It's available for download on App Store.
Skype for iPhone & iTouch allows you make free Skype-to-Skype calls and low cost calls to landlines and mobile phones – and participate in conference calls – from any WiFi zone. You can IM to friends, and participate in group chats too, whenever you have network connectivity, whether it's WiFi, 3G, EDGE or GPRS.
Skype for iPhone & iTouch integrates with your Address Book for low cost calls. It also integrates with the Camera Roll and your photo albums so you can select a profile picture you love.
Download Skype for iPhone & iTouch from App Store