Sudoku Portable is the right choice if you want to have a Sudoku at hand wherever you are, as this application allows you to take it in the USB memory.
In this way you will be able to enjoy it in any place with no worries as regards the installation of the game or to uninstall it every time you finish playing the game.
It includes 4 levels and you may save the games, you may also solve automatically if you can't go on with some problems that the game presents