One common problem when using a centered layout is that when a page is short, the browser does not display a scrollbar, and when your page is taller than a screen, the browser adds a scrollbar. That’s all nice except that your painfully designed content jumps around to accomodate the scrollbar. The solution I have used is to force the scrollbar to appear all the time.

By no mean am I taking credit for this trick. I’ve modified Richard White’s template to incorporate it.

Just include this in your CSS, and voila!

/* force right scrollbar */
html {
    height: 100%;
    margin-bottom: 1px;
}

this will force a vertical scrollbar to appear on the right side.

Update, November 2010. Comment from Brent:

In many cases it is the width of the objects in the body that causes the visual hopping of floated objects. I have found that use of the rule width:auto takes care of many of these issues. Although 4 years old this topic is still high on a Google search and your readers may be interested in this tactic as another means of resolving their issues.

I think this addresses a different issue since the scrollbar appearing will change the width. Having the scrollbar present all the time ensures the width stays contant.