To my thinking, the scroll wheel is the single best invention since, well, the mouse. (If you're still clicking and dragging the scroll bar on the right side of your browser, word processor, or whatever, you're making life unnecessarily hard on yourself.)
Much as I like scrolling with the scroll wheel, however, I dislike the way Firefox moves the page up and down in little jumps. It's distracting, and often causes me to "land" at a different spot on the page than I'd like.
If you're a Firefox user, there's a way to make scrolling more pleasant:
1. Start Firefox.
2. Click Tools, Options.
3. Click the Advanced icon, then look in the Browsing section.
4. Enable Use smooth scrolling, then click OK.
Now try scrolling with your wheel. Much smoother, no? Your mileage may vary, but I find this a much better way to scroll in Firefox.
By the way, there's a similar option in Internet Explorer, but it doesn't seem to do anything--not on my system, anyway, and not with my mouse (a Logitech MX700). Let me know if you've had different results.