well, if you click the scroll-wheel, most browsers should pop up a little scrolly-circle-thing, and then just move your cursor around that to scroll on any direction. up, down, left, right, diagonal.
I know that the Safari for Windows BETA doesn't offer this, because it's an Apple brand product (originally for the Apple Mighty Mouse)
Next time I'll be sure to trim down the pics If your monitor runs on a res higher than 1024x768, then it should look fine.