I'm used to scrolling being thrice as effective as arrowkeys in Firefox.
I want to give the ability to quickly and roughly adjust values by hovering over the slider and using the scrollwheel. Finest adjustments can be made with arrowkeys, but I don't want users to have to switch from mouse to keyboard.
Other options? I'm not entirely comfortable with forcing them to hold e.g. Ctrl-key while scrolling.
Clicking the mousewheel doesn't seem to do the job well either.
Edit: It seems a lot of people are under the misapprehension that dragging the slider as one normally does won't work here. Don't worry; it will. Oh, and numerical input with keyboard is also possible.
Mainly: I wanted to focus this thread on fine adjustment in relation to scrolling and horizontal slider.
Mockup explaining that yes; there are other ways of doing it, so please: rough and fine tuning in relation to slider & scrollwheel :)