Cursorcerer allows you to hide the cursor at any time by use of a global hotkey. It can also autohide an idle cursor and bring it back as soon as you move the mouse.
Useful for hiding the cursor when using the control-scrollwheel zoom trick to make videos and flash content full screen.
To install, just double click on the prefpane. Hit control-option-k to zap and unzap the cursor. If you want to uninstall, go to ~/Library/PreferencePanes/ and trash Cursorcerer.
JWD This program is useful for getting rid of the mouse while watching YouTube in fullscreen, but it has some serious drawbacks:
1. Relies on a daemon that was using 17 MB real memory after one minute of operation (yikes!)
2. No button in the prefpane to activate/deactivate the daemon (had to use Acivity Monitor to quit, don't know if it will come back again at login) (Version 1.0)