WizMouse

Without WizMouse: you place your mouse cursor over the browser window and you start scrolling; but nothing happens because the browser window is not selected.
With WizMouse: you place the mouse cursor over the browser window and you start scrolling; even though the browser window is not selected, scrolling works.

The WizMouse installation file is a very lightweight 544KB in size, so getting it off the web and onto your computer will not take long. You can install WizMouse on 32 and 64-bit versions of Windows 2000, XP, Vista, and Windows 7. Run the aforementioned installation file and a setup wizard will show up and guide you through the installation process.

While this mouse utility is running, you will see a WizMouse icon in the system tray icon. Click it and you will be presented with a menu that lets you access the Configuration window, enable/disable the utility, make a donation, and exit the application. From the aforementioned Configuration window you can set it so WizMouse is enabled/disabled when you left click the tray icon.

WizMouse works like this: enable it and it will send all mouse wheel commands to the window underneath the mouse cursor. By default, Windows sends mouse wheel commands to the currently focused window; WizMouse changes this and sends the commands to the window placed underneath the mouse. This means that you can scroll by simply placing the mouse on top of a window. On top of that, WizMouse can enable mouse wheel for applications that do not offer mouse wheel support.

The WizMouse utility is free. Cons:
None that I could think of.