Our very own Stephen Toub, technical editor of MSDN Magazine, has just published a major article on developing applications for the Tablet PC / UMPC (Ultra-Mobile PC) platform. The article, Microsoft Sudoku: Optimizing UMPC Applications for Touch and Ink, uses the incredibly popular number-puzzle game Sudoku to demonstrate how to enable applications for Touch and Ink. The resulting application - Microsoft Sudoku - will be released as part of the Touch Pack software package, included on all UMPC devices.
Read the article here: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dntablet/html/tbconSudokuSampleFinal.asp (New Link: http://msdn2.microsoft.com/en-us/library/aa480686.aspx).
As an added bonus, the complete source code and Sudoku application are available for download here: http://download.microsoft.com/download/0/6/7/0678a19e-59e9-407d-8326-bbea26b26fb5/SudokuSourceCodeSample.exe. Give it a try - it's addictive :-)