ShapeServices, creator of IM+ instant messenger, have just launched Skype for iPhone, a web-based interface to use Skype services from your iPhone. The application looks amazing, I tried even from Firefox using my Skype account just curious to see the quality and it was great. After login you can call your friends, or landline number if you have skype credits. The application is written in JSP, but seems under high load currently.

iPhone Link: http://skypeforiphone.com/
Website : http://www.shapeservices.com