I have only played with it for a few minutes on my way to work today, and my first impressions are really good. It must be one of the best designed applications that I have tested on the iPhone so far. And for me, it is really the first VoIP application released for the iPhone. Of course, others will argue against me

To able to enter Apple’s AppStore Skype has made some limitations for how and when you can use the application. You can only make free Skype-to-Skype calls and low cost calls to landlines and mobile phones – and participate in conference calls – from WiFi spots. But you can IM and participate in group chats, whenever you have network connectivity, whether it’s WiFi, 3G, EDGE or GPRS. It’s ok for me, and lets me be reachable in new ways, when outside of office.

Skype has made available a great video presenting their product on the iPhone: