This is a great feature from Photoshop CS4 that many don't use. The Flick Panning feature allows you to quickly throw the image canvas around as a way to navigate. It takes a little getting used to, but it feels very natural with a little practice.
- Check your General Preferences to make sure Flick Panning is turned on by Pressing Command+K (Ctrl+K).
- In the General tab, make sure a check mark is next to Enable Flick Panning and click OK.
- Set the the Zoom level set to 400% (or greater) for the image.
- Switch to the Hand tool by pressing H.
- Click to grab the image then quickly move your mouse in the direction you want to flick and release the mouse button.
- To stop the pan, simply wait and let “inertia” kick in or you can click again to stop at a desired point.