I really like the two Sudoku games (one easy, one heavy) ever saturday in our local newspaper -  there are yet only three heavy games I could not solved over the last months and it is really fun. So maybe they are not really "heavy" - who knows.

But now I read this post about how to solve every Sudoku using XSLT (another variant), using SQL and regular expression. Ouch - where is the fun? If you know the algorithm to solve one, it can be expressed by every language poeple like to program. I would more like the algorithm to generate new Sudoku games...