UPDATE: The Photoshop CS3 beta is now available directly from the Adobe Labs, nullifying our earlier coverage of a pulled link (below). In addition, an Adobe spokesperson tells us that a ...

Start Adobe Photoshop CS4. Open the "Help" menu and choose "Deactivate." On the deactivation screen, activate the check box for "Erase This Serial Number" and click on the "Deactivate" button.