I love sudoku puzzles too and do believe they help with the cog fog stuff. I like the look of the text twist stuff too so will check that out. when i am having a day that is a bit too foggy to manage sudoku, i find online mahjong is a reasonable option too.

another game that those of you who like Sudoku may like is called Kakuro - its another number game but based on set combinations only in a grid. Have a look at kakuro.com