If you don’t recall, Towers of Hanoi is a puzzle game where you need to move the entire stack in order to the third spot and when using the other spots you can only put smaller discs on top of larger ones. In fact, it’s available for WM 6.5 for some time. Well in comes Windows Phone 7 and a lot sezier version of the game. Just check it out:
This is the work of Elucidsoft and they noted at it was done in two weeks while working on other projects but all in all it was a 3-4 day project. Here’s another developer who loves the ease of Silverlight and is working on getting 4 apps/games ready for October.