Yes... a fax application! As Jim Courtney writes over on Skype Journal (he was also one of the judges):
The PamConsult team created PamFax to solve the problem of providing a very simple process (especially relative to the somewhat cumbersome WinFax) of using the Internet to easily fax an MS Office document anywhere worldwide. The primary Skype feature here has nothing to do with voice; they used the Skype Extras publishing platform not only to install the application but also as a transaction processor for collecting revenues for the service using Skype credits. Skype Chat is used to send notifications re a fax's delivery. In addition they developed a web-based portal to manage and archive your use of the service. The application can be launched from the Skype Extras menu or from within MS Excel or MS Word. A link to Google Maps will also show roughly where the fax is being sent (to within an Area Code).
The interesting aspect to me is how it uses Skype's micro-payment infrastructure. No need for credit cards or anything... it just debits your Skype Credit. Your Skype Credit, in turn, can be linked to your PayPal account... which can then pull money from credit cards or bank accounts. So you wind up with a very effective and simple way to bill people for services rendered.
Jim goes on to explain a bit more about what PamConsult did:
PamConsult married the Google Maps API's, Microsoft Office COM objects and a backend fax API with their long term experience using the Skype API's. They started a year ago this summer with development of specifications; coding commenced in January with an initial version available in May. After a beta testing program in July, PamFax was released as a Skype Extra in the second week of August.
As noted in the Skype Developer blog post, winners in the US and Japan will be announced at those specific events over the next couple of weeks.
The list of submitted mashups can be found in the Skype Extras gallery. Some look quite intriguing and I'll perhaps write more about them in the future.