Sudoku
Sysquake Remote will solve any sudoku grid that has a unique solution. Just fill all the known cells, and leave unknown ones empty. You can also choose among two grids generated by Sysquake, an easy one and a more challenging one. Other grids are available as PDF: volume 1 (104 KB), 2 (130 KB), 3 (103 KB). Informations on sudoku can be found everywhere, including in Wikipedia.