••  The pointer's flashing is set in this area of the control panel window:

⌥⌥  Click the Never button if you don't want the pointer to flash.  This setting is useful if you set the pointer to move to a specific location on the screen (e.g. under the Apple menu).
⌥⌥  Click the Once, Twice, 3, 4, 5 times button to make the pointer flash a set number of times.  After the last flash the pointer is visible.  The flashing can be stopped anytime by again pressing the hot key or clicking the mouse button while pressing the modifier keys.
⌥⌥  Click the Until next activation button to make the pointer flash until you either press the hot key or you click the mouse button while pressing the modifier keys.  This setting is most useful when the pointer doesn't move.
••  Note that the flashing can be stopped regardless of how many times the pointer will flash.  The pointer is always visible after flashing is stopped (even if it is invisible when the hot key is pressed).
⌥⌥  Click a Flash Rate: button to choose a flash rate.
••  The flash rate varies from once per second to three times per second.
••  Use the slower flash rates on PowerBooks and the faster flash rates on normal video monitors and active-matrix PowerBooks.