I just place my first call using Skype mobile on an iPhone! Currently only available on WiFi, but I'm sure that this will change, as Apple announced that they start to offer vendor free handsets in their Apple retail stores.

Back to Skype. It's clear that the developers put a lot of attention to the interface, and make it appropriately similar to the 'regular' phone interface that iPhone users have come accustomed to.

When you load Skype on your iPhone and log in using your existing Skype ID, it automatically downloads your 'contacts' list from the Skype network. (As some people might know, Skype uses a distributed system to store this information, much like file-sharing software KaZaa or BitTorrent does).

It automatically loads the profile pictures and 'statuses'. You can easily filter contacts that are 'online'.

You can also place 'regular' calls using Skype Out, dialing a number on your keypad or choosing a contact from your address book. When you're out of Skype Credit, you can purchase credit, setup your Skype online number or Voicemail right from the app.

Furthermore, you can set your Skype status update directly from the "Edit Profile" screen, as well as all other profile information.

And lastly, the integrated chat window allows you to leave written messages to your Skype contacts, right from your iPhone.

My first impression with Skype on iPhone is that it's impressively cool. The only downside is that you need WiFi. But that's not so much a bad point for Skype. This one is on Apple's account!

Go ahead and download Skype, right from your iPhone or iTunes!

If, for some reason, you are unable to use the Apple iPhone App Store, read this article for other options of using Skype on your iPhone:
http://blog.tmcnet.com/blog/tom-keating/skype/skype-on-iphone.asp