How to set the diameter for the brush by the mouse scroll wheel?

[gnnbtrn]

How to set the diameter for the brush by the mouse scroll wheel PS CS3?
I'd rather use mouse wheel than keys [ or ] . I keep mu right hand on mouse, and the left hand on the keyboard.
Also, using the [ or ] will increase/decrease the brush size by 10, can I change it to 3 steps?

[goforphoto]

The only way I know of to do this is to click on the brush option icon then click the slider that controls the size then move the wheel. This really is inconvenient due to having to move the curser off the image and open a dropdown box. It is much more effecient to use the bracket keys for sizing the brush. Doing it this way will allow you to keep one hand on the mouse and change brush size with the other.

[PhotosGuy]

Also, using the [ or ] will increase/decrease the brush size by 10, can I change it to 3 steps? Maybe you could make an Action & assign it to an F-key. Not sure how you could get 3 steps from a varying start point though.