Skype for Nokia N800
Working with Nokia's Maemo (later, MeeGo) team in Helsinki, Finland, I was the interaction designer for a standalone Skype application on their N800 and N810 "Internet Tablet" devices.
There were some unique aspects of the project in terms of keeping a somewhat familiar Windows feel to the application - it was loosely based on our Windows Mobile app - while ensuring the app worked equally well with the hardware keys and the in-box stylus.
Much to my delight, I found the N800's Skype client to be very similar to the desktop client in both form and functionality.