The zoom tool (Control and mouse wheel scroll) is normally set to follow the mouse, but sometimes I want both a zoomed-in Flash window and no cursor in the way. In addition to the methods noted this hint that basically hide the cursor, I came across one probably bug-borne trick which allows one to move the cursor without shifting the screen.
First, you zoom in just a little bit, then wait. After a brief delay, the zoom feature will give up and pop back to regular full-screen mode. (The keyboard zoom shortcut, Command-Option-plus, zooms too coarsely to do this -- you must use Control and the mouse wheel.)
After that, zoom back in heartily, and the screen will not doggedly track the mouse anymore! Zooming in and out is still biased by the mouse position, so you can walk the screen a little bit, if need be. Zooming fully back out returns you to normal behavior.
2br
Another way to move the cursor while in zoomed mode without shifting the screen is with a four-button mouse. On any mouse with more than three buttons, you can hold down an extra button, and move the cursor without shifting the zoom display.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20080811051013231