After the mouse itself, the mousewheel is the single greatest navigation tool ever invented. Mine is spinning constantly, especially in Firefox, where I use it to zip up and down Web pages.

By default, however, one "turn" of the mouse wheel scrolls only a few lines at a time--and I want to move faster. Fortunately, there's a fairly easy way to adjust Firefox's scroll speed. Even better, there's a keyboard shortcut that can slow it down again for "precision" scrolling.

First, here's how to change the default scroll speed:

1. Open Firefox, then type about:config in the address bar and hit Enter.

2. In the Filter box, type mousewheel.withnokey.

3. Right-click mousewheel.withnokey.sysnumlines and then click Toggle. This should set the value to False.

4. Right-click mousewheel.withnokey.numlines and then click Modify. Bump the value to 6 or so, click OK, and then switch to another tab to see if you like the scroll speed. (Thankfully, you don't have to restart Firefox every time you make a change.) If not, experiment a bit until you find a number you like.

I keep mine at 7, though there are times when I want--or even need--the option of scrolling more slowly.

Solution: I hold down the Alt key. That drops Firefox back to line-at-a-time scrolling until I release the key. Can't take credit for that killer tip: I read about it over at Lifehacker.