great!
i just noticed Ashish Shetty’s post about his netfx3-based p2p version of sudoku [1], get it at [2].
his implementation takes advantage of windows communication foundation, windows presentation foundation as well as windows workflow foundation, requiring the june ctp available at [3].

for solving your daily sudoku without the need of installing anything you could also point your browser at [4].

[1] http://nerddawg.blogspot.com/2006/07/sudoku.html
[2] sudoku at netfx3.com
[3] netfx3 june ctp
[4] websudoku