Lot's of websites make use of elements on the pages that are meant to be scrolled. As an example, consider the home page of tiptrs, there are two such areas. One bummer about the iPhone is that it can not show the scroll bars of these areas when it is browsing a site that makes use of them. But fear not, there is a way to scroll in these areas.

On the iPhone, while a scroll bar is not shown, scrollable areas are indicated at the bottom of the scrollable section. I can't describe (nor show) the little symbols used, they are subtle and kind of hard to see, but they are there. When you see these, they indicate a section which can be scrolled. When you see these, you can put two fingers side-by-side in that area and use your fingers to scroll just that section (this is similar to scrolling on the Mac TrackPad). The minor gotcha is that you do not sweep your fingers down to scroll in this area (as you would if you were grabbing the scroll bar), you sweep your fingers up to scroll down and sweep your fingers down to scroll up. Seems a little backwards to me, but I'm sure greater minds have determined that this is better.

Using this technique, you can then scroll web pages areas using the iPhone... which is becoming an increasingly used design on web pages.