The Grab And Drag extension provides a number of alternative ways to scroll pages in Firefox, Thunderbird, and Flock. It provides Adobe Acrobat-style grab and drag page scrolling and scrollbar-style scrolling initiated by dragging anywhere on the screen. Grab and Drag also recognizes mouse "Flick" gestures for scrolling up, down, left, or right a screenful at a time, and supports page "Momentum", allowing a page to continue scrolling when dragged at a constant velocity and released.

The extension was originally developed for Tablet PC and UMPC users to aid pen-based navigation. There are currently no plans to extend Grab and Drag to activate with the middle or right mouse buttons. If you're interested in this, I recommend the Scrollbar Anywhere extension instead.

The extension provides three ways to easily toggle functionality on and off:

• A toggle icon can be added to the toolbars via View > Toolbars > Customize...
• Alt-Shift-D toggles functionality on and off
• Holding F2 down is a "quick toggle" for quickly selecting text