You're in a plane en route to your vacation, or perhaps you're waiting to pick up your kids at baseball practice. How do you pass the time? If you're a numbers nut, you probably whip out your beat-up, dog-eared Sudoku puzzle book. They're a quick fix, but eventually you complete all the puzzles in it and have to buy yet another one. And whoops! You've forgotten to bring a pen(cil). Now your puzzle book is useless. Wouldn't it be nice not to have to worry about such things? Then why not go electronic?

Franklin offers handhelds of Sudoku and Kakuro. Both are relatively cheap, easy to use, and offer an astonishing amount of puzzles. Neither handheld has a backlight however, so you'll need to play in brightly lit areas to be able to see their screens.

The Sudoku handheld comes with a stylus and touch screen, which is probably why it's the more expensive of the two at around $24.95 (prices vary slightly depending on the store). It uses G13 batteries (the same in watches, I believe) and comes with them installed. When you turn the Sudoku handheld on, you're greeted by loud and happy, midi-based music that can get annoying once you hear it several times. Mercifully you can turn it off.

The game offers three levels of difficulty (Easy, Medium, and Hard) and there are apparently millions of computer-generated and handcrafted puzzles. Yes, I said millions! The touch screen responds well to the stylus; all you need is a light tap to input your answers. The handheld doesn't come with a protective sack or case, and I'm not sure if scratches will affect the touch screen's sensitivity. Therefore, take some caution when tossing it in your purse or briefcase.

The Sudoku handheld is quite user-friendly. If you make a mistake you can undo your last move or delete that number. Although the game tells you if you've made errors in a puzzle (only after completing it), it doesn't indicate which numbers are incorrect. However, you can sneak a peek at the solution.