With more than 10 million hand-held computers sold each year, it is only reasonable to suppose that plenty of users never master Graffiti -- the Palm operating system's handwriting recognition program -- and that many enter information solely by synchronizing the organizer with a computer. What if some of those people want a mouse, not a stylus?

For such users, Targus has created the PDA Mouse, a stick-on that covers the graffiti writing area of a Palm-based organizer. Functions that are normally activated with the stylus, like the calculator, can be called up by tapping on the corresponding icon on the PDA Mouse. The PDA mouse also has an oval finger wheel that can be used to move the cursor around within any application. A button next to the mouse control acts as the left button of a regular mouse and can start a program.

If a user decides to use Graffiti, one drawback becomes obvious: the stick-on must be removed and the software deactivated.

The PDA mouse has a list price of $19.95 and is available at major electronics outlets and at www.targus.com. Stephen C. Miller